A5051546853- Cellular transport and secretion
- Lipid Membrane Structure and Behavior
- Protein Kinase Regulation and GTPase Signaling
- Receptor Mechanisms and Signaling
- Cholesterol and Lipid Metabolism
- S100 Proteins and Annexins
- Venomous Animal Envenomation and Studies
- RNA and protein synthesis mechanisms
- Protein Structure and Dynamics
- Endoplasmic Reticulum Stress and Disease
- Protease and Inhibitor Mechanisms
- Cancer, Lipids, and Metabolism
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Glycosylation and Glycoproteins Research
- Hedgehog Signaling Pathway Studies
- RNA Interference and Gene Delivery
- Cell death mechanisms and regulation
- Enzyme Catalysis and Immobilization
- Molecular Sensors and Ion Detection
- Inflammatory mediators and NSAID effects
- Neonatal Respiratory Health Research
- Cancer-related gene regulation
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
- Cell Adhesion Molecules Research
- Sphingolipid Metabolism and Signaling
University of Illinois Chicago
2014-2025
University of Illinois Urbana-Champaign
2003-2023
University of Illinois System
2014
University of Notre Dame
2007
Indiana University
2007
Indiana University School of Medicine
2007
University of Michigan
2003
PTEN is a tumor suppressor that reverses the action of phosphoinositide 3-kinase by catalyzing removal 3′ phosphate phosphoinositides. Despite critical role in cell signaling and regulation, mechanisms its membrane recruitment activation still poorly understood. composed an N-terminal phosphatase domain, C2 C-terminal tail region contains PSD-95/Dlg/ZO-1 homology (PDZ) domain-binding sequence multiple phosphorylation sites. Our vitro surface plasmon resonance measurements using immobilized...
Epsin and AP180/CALM are endocytotic accessory proteins that have been implicated in the formation of clathrin-coated pits. Both phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)-binding domains their N termini, but these structurally functionally different. To understand basis distinct properties, we measured PtdIns(4,5)P2-dependent membrane binding epsin N-terminal homology (ENTH) domain AP180 (ANTH) by means surface plasmon resonance monolayer penetration techniques also calculated...
The regulatory domain of conventional protein kinase C (PKC) contains two membrane-targeting modules, the C2 that is responsible for Ca2+-dependent membrane binding protein, and C1 composed cysteine-rich zinc fingers (C1a C1b) bind diacylglycerols phorbol esters. To understand individual roles interplay domains in activation PKC, we functionally expressed isolated PKC-α measured their vesicle monolayer penetration. Results indicate initial Ca2+- phosphatidylserine-dependent electrostatic...
The FYVE domain mediates the recruitment of proteins involved in membrane trafficking and cell signaling to phosphatidylinositol 3-phosphate (PtdIns(3)P)-containing membranes. To elucidate mechanism by which interacts with PtdIns(3)P-containing membranes, we measured binding domains yeast Vps27p Drosophila hepatocyte growth factor-regulated tyrosine kinase substrate their mutants surface plasmon resonance monolayer penetration analyses. These measurements as well electrostatic potential...
The roles of cationic, aliphatic, and aromatic residues in the membrane association dissociation five phospholipases A(2) (PLA(2)), including Asp-49 PLA(2) from venom Agkistrodon piscivorus piscivorus, acidic Naja naja atra, human group IIa V PLA(2)s, C2 domain cytosolic PLA(2), were determined by surface plasmon resonance analysis. Cationic interfacial binding A. p. (Lys-10) (Arg-7, Lys-10, Lys-16), which mediate electrostatic interactions with anionic membranes, primarily accelerate...
Abstract In p53-deficient cancers, targeting cholesterol metabolism has emerged as a promising therapeutic approach, given that p53 loss dysregulates sterol regulatory element-binding protein 2 (SREBP-2) pathways, thereby enhancing biosynthesis. While synthesis inhibitors such statins have shown initial success, their efficacy is often compromised by the development of acquired resistance. Consequently, new strategies are being explored to disrupt homeostasis more comprehensively inhibiting...
On the basis of extensive structure-function studies protein kinase C-α (PKC-α), we have proposed an activation mechanism for conventional PKCs in which C2 domain and C1 interact sequentially with membranes (Medkova, M., Cho, W. (1999) J. Biol. Chem. 274, 19852–19861). To further elucidate interactions between domains during PKC origin phosphatidylserine specificity, mutated several charged residues two (C1a C1b) PKC-α. We then measured membrane binding affinities, activities, monolayer...
Two novel protein kinases C (PKC), PKCdelta and PKCepsilon, have been reported to opposing functions in some mammalian cells. To understand the basis of their distinct cellular regulation, we investigated mechanism vitro sn-1,2-diacylglycerol (DAG)-mediated membrane binding PKCepsilon compared it with that PKCdelta. The regulatory domains PKC contain a C2 domain tandem repeat C1 (C1A C1B), which identified as interaction site for DAG phorbol ester. Isothermal titration calorimetry surface...
Annexin A2 is a phospholipid-binding protein that forms heterotetramer (annexin II-p11 heterotetramer; A2t) with p11 (S100A10). It has been reported annexin involved in binding to phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) and inducing membrane microdomain formation. To understand the mechanisms underlying these findings, we determined properties of wild type mutants both as monomer A2t. Our results from surface plasmon resonance analysis showed A2t modest selectivity for...
Abstract We investigated the role of group V phospholipase A2 (gVPLA2) in OVA-induced inflammatory cell migration and airway hyperresponsiveness (AHR) C57BL/6 mice. Repeated allergen challenge induced biosynthesis gVPLA2 airways. By aerosol, caused dose-related increase resistance saline-treated mice; allergic mice, persistent narrowing. Neither IIa A2, a close homolog gVPLA2, nor W31A, an inactive mutant with reduced activity, narrowing immune-sensitized Pretreatment MCL-3G1, blocking Ab...
Cholesterol is an essential component of the mammalian plasma membrane involved in diverse cellular processes. Our recent quantitative imaging analysis using ratiometric cholesterol sensors showed that available concentration inner leaflet (IPM) low unstimulated cells and increased a stimulus-specific manner to trigger cell signaling events. However, transbilayer distribution remains controversial. Here we report systematic rigorous evaluation basal IPM levels wide range with different...
We reported previously that exogenously added human group V phospholipase A(2) (hVPLA(2)) could elicit leukotriene B(4) (LTB(4)) biosynthesis in neutrophils (Han, S. K., Kim, K. P., Koduri, R., Bittova, L., Munoz, N. M., Leff, A. Wilton, D. C., Gelb, M. H., and Cho, W. (1999) J. Biol. Chem. 274, 11881-11888). To determine the mechanism of hVPLA(2)-induced LTB(4) neutrophils, we thoroughly examined effects hVPLA(2) their lipid products on activity IVA cytosolic PLA(2) (cPLA(2)) under...
Group IVA cytosolic phospholipase A2 (cPLA2) has been shown to play a critical role in the agonist-induced release of arachidonic acid. To understand mechanism by which phosphorylation Ser505 and Ser727 activates cPLA2, we systematically analyzed effects S505A, S505E, S727A, S727E, S505A/S727A, S505A/S727E, S505E/S727E mutations on its enzyme activity membrane affinity. In vitro binding measurements showed that S505A lower affinity than wild type or S505E for phosphatidylcholine membranes,...
Human group V phospholipase A2(hVPLA2) has been shown to have high activity elicit leukotriene production in human neutrophils (Han, S. K., Kim, K. P., Koduri, R., Bittova, L., Munoz, N. M., Leff, A. Wilton, D. C., Gelb, M. H., and Cho, W. (1999)J. Biol. Chem. 274, 11881–11888). To determine the mechanism by which hVPLA2 interacts with cell membranes induce formation, we mutated surface cationic residues a catalytic residue of measured interactions mutants model membranes, immobilized...
Human group IIa phospholipase A2 (hIIa-PLA2) is a highly basic protein that secreted from number of cells during inflammation and may play role in arachidonate liberation destruction invading bacteria. It has been proposed rodent PLA2 anchored to cell surfaces via attachment heparan sulfate proteoglycan this interaction facilitates lipolysis. hIIa-PLA2 contains 13 lysines, 2 histidines, 10 arginines fall into clusters. A panel 26 mutants were prepared which 1-4 residues each cluster changed...
The mechanisms by which cytosolic proteins reversibly bind the membrane and induce curvature for trafficking remodeling remain elusive. epsin N-terminal homology (ENTH) domain has potent vesicle tubulation activity despite a lack of intrinsic molecular curvature. EPR revealed that alpha-helix penetrates phosphatidylinositol 4,5-bisphosphate-containing at unique oblique angle concomitantly interacts closely with helices from neighboring molecules in an antiparallel orientation. quantitative...
Phox homology (PX) domains, which have been identified in a variety of proteins involved cell signaling and membrane trafficking, shown to interact with phosphoinositides (PIs) different affinities specificities. To elucidate the structural origin diverse PI specificity PX we determined crystal structure domain from Bem1p that has reported bind phosphatidylinositol 4-phosphate (PtdIns(4)P). We also measured binding properties its mutants by surface plasmon resonance monolayer techniques...
Lead is a potent environmental toxin that mimics the effects of divalent metal ions, such as zinc and calcium, in context specific molecular targets signaling processes. The mechanism lead toxicity remains poorly understood. objective this work was to characterize effect Pb(2+) on structure membrane-binding properties C2α. C2α peripheral domain Protein Kinase Cα (PKCα), which well-documented target lead. Using NMR isothermal titration calorimetry (ITC) techniques, we established binds with...
Significance Precise manipulation of Hedgehog pathway activity holds great value for biological research and clinical applications, but agonists amenable to engineering have been lacking. We selected a nanobody that potentially targets the conformational changes receptor Patched1 demonstrated this potently activates in vivo. This can serve as basis mechanistic studies activation potential therapeutic applications. Our method may further apply investigation other related transporters...