About

Michael Marletta is a Professor of Chemistry and Molecular and Cell Biology at the University of California, Berkeley, holding the CH and Annie Li Chair in the Molecular Biology of Diseases. Born in 1951, he earned his A.B. from SUNY College at Fredonia in 1973 and his Ph.D. from the University of California, San Francisco in 1978. He completed postdoctoral work as an NIH Fellow at MIT and has held faculty positions at MIT, the University of Michigan, and UC Berkeley. Marletta's research focuses on the interface of chemistry and biology, particularly on protein function and enzyme reaction mechanisms, with an emphasis on molecular understanding of complex biological functions. His laboratory has made significant contributions to understanding nitric oxide (NO) signaling in biology, uncovering key aspects of nitric oxide synthase and soluble guanylate cyclase (sGC), and elucidating gas sensing mechanisms involving heme proteins such as H-NOX. Additionally, his work on cellulose degradation has led to the discovery of a new class of copper-dependent hydroxylases called polysaccharide monooxygenases (PMOs), which play a role in biofuel production and are also studied in pathogenic organisms.

Research topics

• Biochemistry
• Chemistry
• Cell biology
• Biophysics
• Physics
• Combinatorial chemistry
• Biology
• Stereochemistry

Selected publications

• Characterization of an NO-Activated Homodimeric Soluble Guanylate Cyclase from a Choanoflagellate

  Biochemistry · 2025-07-14

  articleSenior authorCorresponding

  Soluble guanylate cyclases are gas-sensing enzymes in eukaryotes that catalyze the formation of cyclic GMP from GTP. While commonly studied sGCs from insects and vertebrates are heterodimers, there are additional classes of homodimeric gas-sensing sGCs in eukaryotes that are not as well characterized. Reported here is the characterization of Cf sGC1 isolated from the organism Choanoeca flexa, a single-celled eukaryote. Cf sGC1 is a homodimeric sGC that exhibits a three-state activation profile in response to NO similar to that observed with heterodimeric NO-responsive sGCs. Cf sGC1 was isolated as an active homodimer, has one heme cofactor per dimer, and exhibits typical substrate saturation kinetics. Small-angle X-ray scattering revealed that Cf sGC1 undergoes a structural change mirroring that of heterodimeric sGCs in the presence of excess NO (relative to the heme concentration). Additionally, two different variants of the C-terminal catalytic domain of Cf sGC1 (sGC1-CAT) were expressed and characterized. The Kd for sGC1-CAT dimerization was 1.8 ± 0.4 μM, compared to the estimated nanomolar affinity of the full-length Cf sGC1 construct. This implies that the N-terminal domains influence enzyme dimerization. Additionally, removal of a predicted disordered C-terminal region of an sGC1-CAT construct gave rise to a construct with ∼3x higher GTP KM compared to the unmodified variant, implying that the disordered tail may enhance enzyme–substrate interactions.

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• Molecular Aspects of Soluble Guanylate Cyclase Activation and Stimulator Function

  Biochemistry · 2025-10-28

  articleSenior authorCorresponding

  Soluble guanylate cyclases (sGCs) are heme-containing, gas-sensing proteins which catalyze the formation of cGMP from GTP. In humans, sGCs are highly selective sensors of nitric oxide (NO) and play a critical role in NO-based regulation of cardiovascular and pulmonary function. The physiological importance of sGC signaling has led to the development of drugs, known as stimulators and activators, which increase sGC catalytic function. Here we characterize a newly developed stimulator, CYR715, which is a particularly potent stimulator of Manduca sexta (Ms) sGC catalytic function even in the absence of NO, increasing activity of the NO-free enzyme to 45% of full catalytic activity. CYR715 also increased the catalytic activity of Ms sGC βC122A and βC122S variants, with a marked stimulation of the NO-free βC122S variant to 74% of maximum. High-resolution cryo-electron microscopy structures were solved for CYR715 bound to Ms sGC βC122S revealing that CYR715 occupies the same binding site as the characterized sGC stimulators YC-1 and riociguat. Additionally, the core scaffold of CYR715 makes a binding interaction with βC78 while the flexible tail can interact with αR429 or βY7 and E361. Conformational extension of sGC following NO, YC-1, or CYR715 binding was characterized using small-angle X-ray scattering, revealing that while ligand binding results in sGC extension this extension does not directly correlate to observed activity. This suggests that not all conformational extensions of sGC result in increased catalytic activity, and that effective stimulators assist in converting extension into catalytic function.

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• Second-Sphere Histidine Catalytic Function in a Fungal Polysaccharide Monooxygenase

  Biochemistry · 2024-11-20 · 2 citations

  articleSenior authorCorresponding

  Fungal polysaccharide monooxygenases (PMOs) oxidatively degrade cellulose and other carbohydrate polymers via a mononuclear copper active site using either O2 or H2O2 as a cosubstrate. Cellulose-active fungal PMOs in the auxiliary activity 9 (AA9) family have a conserved second-sphere hydrogen-bonding network consisting of histidine, glutamine, and tyrosine residues. The second-sphere histidine has been hypothesized to play a role in proton transfer in the O2-dependent PMO reaction. Here the role of the second-sphere histidine (H157) in an AA9 PMO, MtPMO9E, was investigated. This PMO is active on soluble cello-oligosaccharides such as cellohexaose (Glc6), thus enabling kinetic analysis with the point variants H157A and H157Q. The variants appeared to fold similarly to the wild-type (WT) enzyme and yet exhibited weaker affinity toward Glc6 than WT (WT KD = 20 ± 3 μM). The variants had comparable oxidase (O2 reduction to H2O2) activity to WT at all pH values tested. Using O2 as a cosubstrate, the variants were less active for Glc6 hydroxylation than WT, with H157A being the least active. Similarly, H157Q was competent for Glc6 hydroxylation with H2O2, but H157A was less active. Comparison of the crystal structures of H157Q and WT MtPMO9E reveals that a terminal heteroatom of Q157 overlays with Nε of H157. Altogether, the data suggest that H157 is not important for proton transfer, but support a role for H157 as a hydrogen-bond donor to diatomic-oxygen intermediates, thus facilitating catalysis with either O2 or H2O2.

  PublisherDOI

• Molecular aspects of sGC activation and stimulator function

  2024-04-21

  articleOpen access1st authorCorresponding

  <p class="first" dir="auto" id="d1083939e137">Mammalian sGC is a heterodimer composed of α- and β-subunits. The C-terminus of each subunit contains a catalytic domain and the active site is composed of residues from both subunits. The catalytic domains also form a pseudosymmetric site that contains residues known to be involved in nucleotide binding, but lack the complete complement of amino acids required for catalysis. Sequence analysis shows that each subunit also contains well-defined PAS-like domain, and a predicted coiled-coil region. The N-termini of the α- and β-subunits are homologous to the H-NOX ( <span style="text-decoration: underline">H</span>eme- <span style="text-decoration: underline">N</span>itric oxide/ <span style="text-decoration: underline">OX</span>ygen) family of proteins. The N-terminus of β-subunit contains a ferrous heme cofactor that serves a receptor for NO. Additional studies point toward a more complicated role for NO and stimulators in the regulation of activity. Structural and biochemical results have broadened the current molecular view of the regulation of sGC and provide a framework to understand the action of sGC modulators of activity. Activity and structural studies involved with regulation will be discussed. NO also functions as a signaling molecule in Choanoflagellates. Choanoflagellates are a group of free-living unicellular and eukaryotes considered to be the closest living relatives of the animals. The evolutionary history of NO signaling is proving to be informative on function.

  PublisherOA PDFDOI

• Electron transfer in polysaccharide monooxygenase catalysis

  Proceedings of the National Academy of Sciences · 2024-12-30 · 3 citations

  articleOpen accessSenior authorCorresponding

  Polysaccharide monooxygenase (PMO) catalysis involves the chemically difficult hydroxylation of unactivated C–H bonds in carbohydrates. The reaction requires reducing equivalents and will utilize either oxygen or hydrogen peroxide as a cosubstrate. Two key mechanistic questions are addressed here: 1) How does the enzyme regulate the timely and tightly controlled electron delivery to the mononuclear copper active site, especially when bound substrate occludes the active site? and 2) How does this electron delivery differ when utilizing oxygen or hydrogen peroxide as a cosubstrate? Using a computational approach, potential paths of electron transfer (ET) to the active site copper ion were identified in a representative AA9 family PMO from Myceliophthora thermophila ( Mt PMO9E). When Y62, a buried residue 12 Å from the active site, is mutated to F, lower activity is observed with O 2 . However, a WT-level activity is observed with H 2 O 2 as a cosubstrate indicating an important role in ET for O 2 activation. To better understand the structural effects of mutations to Y62 and axial copper ligand Y168, crystal structures were solved of the wild type Mt PMO9E and the variants Y62W, Y62F, and Y168F. A bioinformatic analysis revealed that position 62 is conserved as either Y or W in the AA9 family. The Mt PMO9E Y62W variant has restored activity with O 2 . Overall, the use of redox-active residues to supply electrons for the reaction with O 2 appears to be widespread in the AA9 family. Furthermore, the results provide a molecular framework to understand catalysis with O 2 versus H 2 O 2 .

  PublisherDOI

• Allosteric activation of choanoflagellate soluble guanylate cyclases

  Acta Crystallographica Section A Foundations and Advances · 2023-07-07

  articleOpen accessSenior author

  Nitric oxide (NO) is a signaling molecule used by animals in key processes like vasodilation, neurotransmission, and host response to infection.Central to NO function in animal physiology is the metalloenzyme soluble guanylate cyclase (sGC), which generates the secondary messenger guanosine 3',5'-monophosphate (cGMP) in response to allosteric activation by NO.Because of its centrality to several physiological processes in humans, sGC is a current therapeutic target, and a complete structural and mechanistic understanding of the 3-stage activation of sGC by NO will inform continued development.Newly discovered sGCs from the single-celled colonial organism Choanoeca flexa have recently been shown to display regulation profiles similar to those of animals but with several conspicuous structural differences.Importantly, choanoflagellates like C. flexa are the closest singlecelled relatives to animals, and their NO colonial signaling may represent a major step toward the evolution of multicellularity.Using structural techniques including small-angle X-ray scattering and cryo-EM, I characterize the unique properties of C. flexa sGC to better understand the allostery of sGCs and shed light on the evolution of NO signal transduction in animals.

  PublisherDOI

• Characterization of a unique polysaccharide monooxygenase from the plant pathogen <i>Magnaporthe oryzae</i>

  Proceedings of the National Academy of Sciences · 2023-02-15 · 17 citations

  articleOpen accessSenior author

  Blast disease in cereal plants is caused by the fungus Magnaporthe oryzae and accounts for a significant loss in food crops. At the outset of infection, expression of a putative polysaccharide monooxygenase ( Mo PMO9A) is increased. Mo PMO9A contains a catalytic domain predicted to act on cellulose and a carbohydrate-binding domain that binds chitin. A sequence similarity network of the Mo PMO9A family AA9 showed that 220 of the 223 sequences in the Mo PMO9A-containing cluster of sequences have a conserved unannotated region with no assigned function. Expression and purification of the full length and two Mo PMO9A truncations, one containing the catalytic domain and the domain of unknown function (DUF) and one with only the catalytic domain, were carried out. In contrast to other AA9 polysaccharide monooxygenases (PMOs), Mo PMO9A is not active on cellulose but showed activity on cereal-derived m ixed (1→3, 1→4)- β -D- g lucans (MBG). Moreover, the DUF is required for activity. Mo PMO9A exhibits activity consistent with C4 oxidation of the polysaccharide and can utilize either oxygen or hydrogen peroxide as a cosubstrate. It contains a predicted 3-dimensional fold characteristic of other PMOs. The DUF is predicted to form a coiled-coil with six absolutely conserved cysteines acting as a zipper between the two α-helices. Mo PMO9A substrate specificity and domain architecture are different from previously characterized AA9 PMOs. The results, including a gene ontology analysis, support a role for Mo PMO9A in MBG degradation during plant infection. Consistent with this analysis, deletion of Mo PMO9A results in reduced pathogenicity.

  PublisherOA PDFDOI

• Proteases influence colony aggregation behavior in Vibrio cholerae

  Journal of Biological Chemistry · 2023-10-26 · 4 citations

  articleOpen accessSenior authorCorresponding

  Aggregation behavior provides bacteria protection from harsh environments and threats to survival. Two uncharacterized proteases, LapX and Lap, are important for Vibrio cholerae liquid-based aggregation. Here, we determined that LapX is a serine protease with a preference for cleavage after glutamate and glutamine residues in the P1 position, which processes a physiologically based peptide substrate with a catalytic efficiency of 180 ± 80 M-1s-1. The activity with a LapX substrate identified by a multiplex substrate profiling by mass spectrometry screen was 590 ± 20 M-1s-1. Lap shares high sequence identity with an aminopeptidase (termed VpAP) from Vibrio proteolyticus and contains an inhibitory bacterial prepeptidase C-terminal domain that, when eliminated, increases catalytic efficiency on leucine p-nitroanilide nearly four-fold from 5.4 ± 4.1 × 104 M−1s−1 to 20.3 ± 4.3 × 104 M−1s−1. We demonstrate that LapX processes Lap to its mature form and thus amplifies Lap activity. The increase is approximately eighteen-fold for full-length Lap (95.7 ± 5.6 × 104 M−1s−1) and six-fold for Lap lacking the prepeptidase C-terminal domain (11.3 ± 1.9 × 105 M−1s−1). In addition, substrate profiling reveals preferences for these two proteases that could inform in vivo function. Furthermore, purified LapX and Lap restore the timing of the V. cholerae aggregation program to a mutant lacking the lapX and lap genes. Both proteases must be present to restore WT timing, and thus they appear to act sequentially: LapX acts on Lap, and Lap acts on the substrate involved in aggregation. Aggregation behavior provides bacteria protection from harsh environments and threats to survival. Two uncharacterized proteases, LapX and Lap, are important for Vibrio cholerae liquid-based aggregation. Here, we determined that LapX is a serine protease with a preference for cleavage after glutamate and glutamine residues in the P1 position, which processes a physiologically based peptide substrate with a catalytic efficiency of 180 ± 80 M-1s-1. The activity with a LapX substrate identified by a multiplex substrate profiling by mass spectrometry screen was 590 ± 20 M-1s-1. Lap shares high sequence identity with an aminopeptidase (termed VpAP) from Vibrio proteolyticus and contains an inhibitory bacterial prepeptidase C-terminal domain that, when eliminated, increases catalytic efficiency on leucine p-nitroanilide nearly four-fold from 5.4 ± 4.1 × 104 M−1s−1 to 20.3 ± 4.3 × 104 M−1s−1. We demonstrate that LapX processes Lap to its mature form and thus amplifies Lap activity. The increase is approximately eighteen-fold for full-length Lap (95.7 ± 5.6 × 104 M−1s−1) and six-fold for Lap lacking the prepeptidase C-terminal domain (11.3 ± 1.9 × 105 M−1s−1). In addition, substrate profiling reveals preferences for these two proteases that could inform in vivo function. Furthermore, purified LapX and Lap restore the timing of the V. cholerae aggregation program to a mutant lacking the lapX and lap genes. Both proteases must be present to restore WT timing, and thus they appear to act sequentially: LapX acts on Lap, and Lap acts on the substrate involved in aggregation. Bacteria form community aggregates that aid their survival in hostile environments (1Vestby L.K. Grønseth T. Simm R. Nesse L.L. Bacterial biofilm and its role in the pathogenesis of disease.Antibiotics. 2020; 9: 59Crossref Scopus (382) Google Scholar), including those encountered during pathogenesis (2Høiby N. A short history of microbial biofilms and biofilm infections.APMIS. 2017; 125: 272-275Crossref PubMed Scopus (112) Google Scholar, 3Trunk T. Khalil H.S. Leo J.C. Bacterial autoaggregation.AIMS Microbiol. 2018; 4: 140-164Crossref PubMed Google Scholar). In particular, Vibrio cholerae, the bacterium that causes the cholera disease, exhibits two modes of community formation: surface-associated biofilms and liquid-based aggregates. Both pathways are controlled by quorum sensing, a cell-to-cell communication process (4Jemielita M. Wingreen N.S. Bassler B.L. Quorum sensing controls Vibrio cholerae multicellular aggregate formation.Elife. 2018; 7e42057Crossref PubMed Scopus (37) Google Scholar, 5Boyaci H. Shah T. Hurley A. Kokona B. Li Z. Ventocilla C. et al.Structure, regulation, and inhibition of the quorum-sensing signal integrator LuxO.PLOS Biol. 2016; 14e1002464Crossref PubMed Scopus (37) Google Scholar, 6Papenfort K. Silpe J.E. Schramma K.R. Cong J.-P. Seyedsayamdost M.R. Bassler B.L. A Vibrio cholerae autoinducer-receptor pair that controls biofilm formation.Nat. Chem. Biol. 2017; 13: 551-557Crossref PubMed Scopus (126) Google Scholar). Specifically, at low cell density, V. cholerae forms surface biofilms, dispersing from them at high cell density. Multiple matrix components are required for surface biofilm formation. By contrast, the V. cholerae liquid aggregation program occurs at high cell density and does not rely on canonical biofilm matrix components. Since V. cholerae strains that form aggregate communities are more virulent than those that cannot, it is hypothesized that liquid aggregate formation is crucial for V. cholerae to successfully transit between the marine niche and the human host (7Faruque S.M. Biswas K. Udden S.M.N. Ahmad Q.S. Sack D.A. Nair G.B. et al.Transmissibility of cholera: in vivo-formed biofilms and their relationship to infectivity and persistence in the environment.Proc. Natl. Acad. Sci. U. S. A. 2006; 103: 6350-6355Crossref PubMed Scopus (255) Google Scholar, 8Tamayo R. Patimalla B. Camilli A. Growth in a biofilm induces a hyperinfectious phenotype in Vibrio cholerae.Infect. Immun. 2010; 78: 3560-3569Crossref PubMed Scopus (139) Google Scholar, 9Nelson E.J. Chowdhury A. Harris J.B. Begum Y.A. Chowdhury F. Khan A.I. et al.Complexity of rice-water stool from patients with Vibrio cholerae plays a role in the transmission of infectious diarrhea.Proc. Natl. Acad. Sci. U. S. A. 2007; 104: 19091-19096Crossref PubMed Scopus (51) Google Scholar). Thus, understanding the molecular mechanisms underlying aggregation could enable development of new therapeutics. At present, little is known about the high cell density, liquid-based V. cholerae aggregation mechanism. Bacterial aggregation often involves an outer-membrane autotransporter that self-associates and can contain protease domains (10Khalil H.S. Øgaard J. Leo J.C. Coaggregation properties of trimeric autotransporter adhesins.Microbiologyopen. 2020; 9: e1109Crossref PubMed Scopus (4) Google Scholar, 11Béchon N. Jiménez-Fernández A. Witwinowski J. Bierque E. Taib N. Cokelaer T. et al.Autotransporters drive biofilm formation and autoaggregation in the diderm firmicute veillonella parvula.J. Bacteriol. 2020; 202e00461-20Crossref PubMed Scopus (14) Google Scholar, 12Nwoko E.Q.A. Okeke I.N. Bacteria autoaggregation: and bacteria PubMed Scopus Google Scholar). a aggregation from contains a protease domain at the by a that is in the bacterial which to aggregation. A increases that plays a role in aggregation The serine protease and by a host PubMed Google Scholar). at the of identified in H. S. A. H. S. et new of from and role of for and of the PubMed Scopus Google Scholar). The of in H. is the of is with V. cholerae activity aggregation in the and it in the the that activity can of bacterial aggregation formation. In V. cholerae, proteases are involved in the liquid-based aggregation and Lap M. Wingreen N. Bassler B.L. proteases the timing of community formation in Scholar). proteases are A mutant V. cholerae lacking proteases a in the of the aggregation phenotype than a mutant lacking Lap and LapX M. Wingreen N. Bassler B.L. proteases the timing of community formation in of Lap and LapX to the V. cholerae and are known to in Vibrio including of during M. Vibrio cholerae and F. M. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar), of host K. B. R. T. The from Vibrio cholerae and J. PubMed Scopus Google Scholar), and of K. of the Vibrio cholerae are by Bacteriol. PubMed Scopus Google Scholar), a involved in and R. A. B. H. S. et of Vibrio cholerae involves a between and Immun. PubMed Scopus Google Scholar, E. A. R. et Vibrio cholerae a that to host Scopus Google Scholar). in aggregation is the and identified role for LapX and Lap and a new molecular underlying of bacterial aggregation (4Jemielita M. Wingreen N.S. Bassler B.L. Quorum sensing controls Vibrio cholerae multicellular aggregate formation.Elife. 2018; 7e42057Crossref PubMed Scopus (37) Google Scholar, M. Wingreen N. Bassler B.L. proteases the timing of community formation in Scholar). The substrate and the that LapX and Lap in the aggregation phenotype are the of the aggregates substrate the more can be about Lap it shares high sequence identity with a that from Vibrio proteolyticus The a S. and sequence of the Vibrio proteolyticus aminopeptidase PubMed Scopus Google Scholar, B. and of to the aminopeptidase from PubMed Scopus Google Scholar, The aminopeptidase from and of involved in peptide Chem. Scopus Google Scholar, B. and of the and leucine from Chem. PubMed Scopus Google Scholar, C. Harris of the leucine aminopeptidase from for an Biol. Chem. PubMed Google Scholar). LapX is a to be a serine protease it contains a catalytic we present a of LapX and We demonstrate that LapX processes Lap to a mature of to an V. cholerae that the lapX and lap the WT aggregation LapX and Lap lacking domains that are required to with a protease in which LapX must process Lap in for Lap to be in the aggregation The and are to in an on the V. cholerae and the LapX and Lap M. Wingreen N. Bassler B.L. proteases the timing of community formation in A and The of which that LapX and Lap are required for V. cholerae is not M. Wingreen N. Bassler B.L. proteases the timing of community formation in we on LapX and LapX is a leucine a serine protease that to the A of the of the A in reveals of sequence with serine proteases reveals of the catalytic and Lap is a leucine Lap was purified and to activity on a substrate C. and of the Vibrio cholerae aminopeptidase Immun. PubMed Google Scholar). A that shares sequence and S. and sequence of the Vibrio proteolyticus aminopeptidase PubMed Scopus Google Scholar, B. and of to the aminopeptidase from PubMed Scopus Google Scholar, The aminopeptidase from and of involved in peptide Chem. Scopus Google Scholar, B. and of the and leucine from Chem. PubMed Scopus Google Scholar, M. B. and of Vibrio proteolyticus a PubMed Scopus Google Scholar). two in the and exhibits aminopeptidase including activity on of aminopeptidase and Biol. Chem. PubMed Google Scholar). The that in are in Lap and in that Lap is a Both proteases to a sequence and Since Vibrio Vibrio a liquid-based aggregation behavior to that in V. cholerae M. Wingreen N. 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The LapX an between the and the catalytic The catalytic domain exhibits a by two domains to by an of the LapX is the catalytic and which are in The protease domain of Lap the of the A the Lap domain to the The of the the of the and the of with their protease domains the during to proteases A. of and inhibition for the protease Biol. Chem. PubMed Scopus Google Scholar), and are to substrate to the Both LapX and Lap contain a sequence and are LapX and Lap in the the sequence was with a sequence for to the The the in the and a C-terminal for of The full-length domains in the of the in protease a Lap lacking the C-terminal domain was with a LapX lacking the C-terminal domain for the and for LapX and Lap are in and The during are to by E. proteases in the of to We these to of domains and of LapX and LapX controls for Lap and Lap contain and of the two for its Both on the substrate for The Lap activity than Lap is with of Lap C. and of the Vibrio cholerae aminopeptidase Immun. PubMed Google and its M. B. and of Vibrio proteolyticus a PubMed Scopus Google Scholar), which protease activity when Lap substrate multiplex substrate spectrometry was to Lap and Lap and a peptide to protease substrate preference J. M. J.B. et of by multiplex substrate 9: PubMed Scopus Google Scholar). is a to on the of and for The peptide from in the and the of and for are aminopeptidase and from for of a substrate for of protease behavior and could be to it is an and not of peptide from the protease are not and not aid in the of is peptide and cleavage their Thus, was to the peptide substrate of the two Lap and two LapX and to the A with the for is Both Lap aminopeptidase activity with a cleavage preference for in the The Lap for residues at the substrate P1 cleavage aminopeptidase activity the P1 is the We and cleavage the to the of residues on the of Lap and Lap the for with by in the at the P1 was the at the P1 for Lap and the for the Lap are in substrate preferences between the two the of LapX and LapX with cleavage and of the to be a of during we LapX could a in the of which to the of the with the of the was not by the serine protease serine protease is with the that aggregation in V. cholerae occurs when is present (4Jemielita M. Wingreen N.S. Bassler B.L. Quorum sensing controls Vibrio cholerae multicellular aggregate formation.Elife. 2018; 7e42057Crossref PubMed Scopus (37) Google Scholar). LapX was not by The serine was to in LapX and LapX We these LapX and LapX purified and for activity. in the of that are with for the the LapX substrate LapX and LapX to J. M. J.B. et of by multiplex substrate 9: PubMed Scopus Google Scholar, Z. substrate profiling by mass spectrometry for PubMed Scopus Google Scholar). We that of LapX could a role for the C-terminal domain in substrate domain is and its is with the two activity and in at position, with preferences for and preferences for at the P1 and the an peptide was J. R. A. T. M. et with PubMed Scopus Google Scholar), to the peptide we an peptide substrate to the cleavage of a substrate a at the P1 The the of the does not the for in that these two they to be the are in is to with the the to to for proteases J. M. J.B. et of by multiplex substrate 9: PubMed Scopus Google Scholar, Z. substrate profiling by mass spectrometry for PubMed Scopus Google Scholar). to of LapX a was in the serine to The peptide was with of ± × for LapX and ± × for LapX are than that for the peptide with at the P1 with of ± × and ± × for LapX and LapX to be a of on the of LapX and LapX peptide for LapX in a new it was that of the Lap was to the aminopeptidase its mature form M. B. and of Vibrio proteolyticus a PubMed Scopus Google Scholar). Since lapX is with it was to LapX on Lap was with catalytic of LapX and the was by LapX does Lap to a mature that process is by LapX and not by Lap we activity with a of that protease and LapX of Lap was not by an protease by at a than that of of LapX that Lap is in these LapX and at a than that of the process of more the of on the of J. 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C. M. E. for serine 13: PubMed Scopus Google Scholar, A. M. M. S. R. et from protease from a with a serine protease PubMed Scopus Google Scholar). is not by the at of a protease PubMed Scopus Google Scholar). The LapX and LapX the activity of the that contain an at the P1 and is with the with LapX cleavage of the peptide was with the and the LapX and LapX are in and to its mature form by LapX the Lap and and and The of the Lap was determined by mass spectrometry and and the sequence by The are with for V. cholerae Lap and C. Harris of the leucine aminopeptidase from for an Biol. Chem. PubMed Google Scholar, C. and of the Vibrio cholerae aminopeptidase Immun. PubMed Google Scholar). A Lap residues to was that to the cleavage and domain to the that at the determined by and to We a in the mass that to that the after the catalytic domain Lap was the and purified to and Lap purified Lap low and thus exhibits low catalytic activity and that the is important for and the for Lap on × × × × × × × × 104 in a new LapX and Lap the timing of V. cholerae aggregation M. Wingreen N. Bassler B.L. proteases the timing of community formation in Scholar). Here, the of LapX Lap to restore timing to aggregate formation was V. cholerae of lapX lap causes a in aggregation M. Wingreen N. Bassler B.L. proteases the timing of community formation in A and of LapX to a mutant and Lap to a mutant the aggregate formation timing The proteases for by the of Lap to the mutant and of LapX to the mutant with LapX and Lap was required to restore WT aggregation timing to the mutant A and Thus, proteases are required for timing of aggregate formation. M. Wingreen N. Bassler B.L. proteases the timing of community formation in Scholar), of the of lapX and lap on the V. cholerae does not aggregate formation timing of purified not V. cholerae aggregate including in a The role of the LapX C-terminal domains and in V. cholerae aggregate formation was the of purified LapX and purified LapX to the aggregation timing The LapX C-terminal domain is for aggregation formation the LapX to the aggregation timing purified LapX in the V. cholerae mutant LapX the when present in LapX LapX to the aggregation timing by the the in that LapX not the LapX C-terminal is required to process the Lap protease and LapX and Lap are required for WT aggregation timing in V. LapX and Lap are proteases that to in the liquid-based aggregation process of V. we that LapX in the of and the of LapX is a of a serine protease with it contains a catalytic of these serine proteases and exhibits activity. The lapX to lap to a a serine protease in Vibrio that be in Vibrio proteases LapX and Lap are often mechanisms for the of to Sci. PubMed Google Scholar), which provides their and often involves an C-terminal inhibitory that the are with known bacterial A. in bacterial Microbiol. PubMed Scopus Google Scholar). proteases successfully they during to the of to an E. protease protease not during to with LapX a substrate preference that is determined by and at the P1 LapX low activity on peptide these activity proteases are not with LapX activity than that for the and of PubMed Scopus Google Scholar), serine to serine proteases, low activity. is to its catalytic than the canonical that LapX a its be to a important for that to domains for B. peptide the by protease of inhibition by its PubMed Scopus Google and J. J. V. A. R. et of the domains in Bacteriol. 2007; PubMed Scopus Google Scholar). Since contain it is that these not that the of of protease that substrate cleavage Chem. 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  PublisherOA PDFDOI

• Role of the Coiled-Coil Domain in Allosteric Activity Regulation in Soluble Guanylate Cyclase

  Biochemistry · 2023-05-02 · 8 citations

  articleOpen accessSenior authorCorresponding

  Soluble guanylate cyclase (sGC) is the primary nitric oxide (NO) receptor in higher eukaryotes, including humans. NO-dependent signaling via sGC is associated with important physiological effects in the vascular, pulmonary, and neurological systems, and sGC itself is an established drug target for the treatment of pulmonary hypertension due to its central role in vasodilation. Despite isolation in the late 1970s, high-resolution structural information on full-length sGC remained elusive until recent cryo-electron microscopy structures were determined of the protein in both the basal unactivated state and the NO-activated state. These structures revealed large-scale conformational changes upon activation that appear to be centered on rearrangements within the coiled-coil (CC) domains in the enzyme. Here, a structure-guided approach was used to engineer constitutively unactivated and constitutively activated sGC variants through mutagenesis of the CC domains. These results demonstrate that the activation-induced conformational change in the CC domains is necessary and sufficient for determining the level of sGC activity.

  PublisherOA PDFDOI

• Nitric oxide signaling controls collective contractions in a colonial choanoflagellate

  Current Biology · 2022-05-02 · 21 citations

  articleOpen accessCorresponding

  et la diffusion de documents scientifiques de niveau recherche, publis ou non, manant des tablissements d'enseignement et de recherche franais ou trangers, des laboratoires publics ou privs.

  PublisherOA PDFDOI

Recent grants

• Mechanism of fungal polysaccharide monooxygenases

  NSF · $500k · 2015–2018

• NIH Grant R01GM070671

  NIH · $1.2M · 2009

• Activation Mechanism of Soluble Guanylate Cyclase

  NIH · $1.3M · 2019–2022

• NIH Grant R01CA050414

  NIH · $1.4M · 1999

• NIH Grant R01GM077365

  NIH · $1.0M · 2011

Frequent coauthors

• Sönke Behrends

  Technische Universität Braunschweig

  137 shared

• Nur Başak Sürmeli

  Izmir Institute of Technology

  130 shared

• Michael Mueller

  Mayo Clinic

  121 shared

• Almaz Aldashev

  121 shared

• John Wharton

  Imperial College London

  121 shared

• Martin R. Wilkins

  Imperial College London

  121 shared

• Nicholas W. Morrell

  121 shared

• Shriram G. Bhosle

  121 shared

Labs

• Michael Marletta LaboratoryPI

Education

• Ph.D., Pharmaceutical Chemistry

  UCSF Medical Center

  1977

• A.B., Chemistry and Biology

  SUNY Fredonia

  1973

Awards & honors

• George H. Hitchings Award, Innovative Methods in Drug Discov…
• Faculty recognition Award, The University of Michigan (1992)
• Outstanding Alumni Achievement Award, S.U.N.Y. College at Fr…
• MacArthur Foundation Fellowship (1995)
• S.U.N.Y. Alumni Honor Roll (1996)