Gastric ezrin is a 80kDa protein, which is highly enriched in apical microvilli of gastric parietal cells and with sequence homology to talin and erythrocyte band 4.1. Ezrin has beensuggested to play a key role in mediating the apical surface rearrangements involved in acid secretion by parietal cells. The mediation of stimulation of acid secretion by the cAMP-dependent protein kinase A pathway has been correlated with the phosphorylation of ezrin. These studies suggest that phosphorylation is at serine/threonine residues and not at tyrosine residues. On the other hand, ezrin in A431 cells which overexpresses EGF receptors was characterized as a substrate for an EGF-stimulated tyrosine kinase and was phosphorylated at bothserine and tyrosine residues (Brestcher et al., 1989). EGF inhibited acid secretion in parietal cells and it has been suggested that EGF-stimulated tyrosine phosphorylation of ezrin might itself inhibit stimulation. In this project we propose to examine the site-directed phosphorylation of ezrin by histamine and EGF which stimulate and inhibit acid secretion respectively and identify the in vivo phosphorylation sites in each case. Our experimental strategy would involve proteolysis of ezrin in gel slices, followed by purification of phosphopeptides on iron-loaded (FeIII) nitriloacetic (NTA) sepaharose columns, the separation of the phosphopeptides by HPLC and the identification of the specific Ser, Thr or Tyr phosphorylated, by MALDI mass spectrometry and post-source decay analysis.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001614-19
Application #
6308849
Study Section
Project Start
2000-03-01
Project End
2002-02-28
Budget Start
1998-10-01
Budget End
1999-09-30
Support Year
19
Fiscal Year
2000
Total Cost
$9,880
Indirect Cost
Name
University of California San Francisco
Department
Type
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
MacRae, Andrew J; Mayerle, Megan; Hrabeta-Robinson, Eva et al. (2018) Prp8 positioning of U5 snRNA is linked to 5' splice site recognition. RNA 24:769-777
Katsuno, Yoko; Qin, Jian; Oses-Prieto, Juan et al. (2018) Arginine methylation of SMAD7 by PRMT1 in TGF-?-induced epithelial-mesenchymal transition and epithelial stem-cell generation. J Biol Chem 293:13059-13072
Sahoo, Pabitra K; Smith, Deanna S; Perrone-Bizzozero, Nora et al. (2018) Axonal mRNA transport and translation at a glance. J Cell Sci 131:
Tran, Vy M; Wade, Anna; McKinney, Andrew et al. (2017) Heparan Sulfate Glycosaminoglycans in Glioblastoma Promote Tumor Invasion. Mol Cancer Res 15:1623-1633
Liu, Tzu-Yu; Huang, Hector H; Wheeler, Diamond et al. (2017) Time-Resolved Proteomics Extends Ribosome Profiling-Based Measurements of Protein Synthesis Dynamics. Cell Syst 4:636-644.e9
Bikle, Daniel D (2016) Extraskeletal actions of vitamin D. Ann N Y Acad Sci 1376:29-52
Twiss, Jeffery L; Fainzilber, Mike (2016) Neuroproteomics: How Many Angels can be Identified in an Extract from the Head of a Pin? Mol Cell Proteomics 15:341-3
Cil, Onur; Phuan, Puay-Wah; Lee, Sujin et al. (2016) CFTR activator increases intestinal fluid secretion and normalizes stool output in a mouse model of constipation. Cell Mol Gastroenterol Hepatol 2:317-327
Posch, Christian; Sanlorenzo, Martina; Vujic, Igor et al. (2016) Phosphoproteomic Analyses of NRAS(G12) and NRAS(Q61) Mutant Melanocytes Reveal Increased CK2? Kinase Levels in NRAS(Q61) Mutant Cells. J Invest Dermatol 136:2041-2048
Julien, Olivier; Zhuang, Min; Wiita, Arun P et al. (2016) Quantitative MS-based enzymology of caspases reveals distinct protein substrate specificities, hierarchies, and cellular roles. Proc Natl Acad Sci U S A 113:E2001-10

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