Biochemical characterization of valosin-containing protein, a protein tyrosine kinase substrate in hematopoietic cells.
Engagement of the T cell antigen receptor (TCR) leads to activation of multiple tyrosine kinases and rapid tyrosine phosphorylation of intracellular protein substrates. A number of these substrates have been identified and they include TCR subunits, phospholipase C-gamma 1, p95vav, and ezrin. In a recent study we have demonstrated that VCP (valosin-containing protein) becomes tyrosine phosphorylated upon TCR cross-linking. Analysis of the predicted amino acid sequence of this protein indicates that it is a member of a family of oligomeric proteins containing duplicated domains with predicted ATPase activity. In the current study we determine the site of tyrosine phosphorylation in VCP, demonstrate that murine VCP indeed is an oligomeric ATPase, and show that the tyrosine phosphorylation of the protein has no effect on VCP ATPase activity. Recent evidence suggests that VCP associates with clathrin. A possible role of tyrosine phosphorylation in regulating this protein-protein interaction is discussed.
Egerton
M
M
Cell Biology and Metabolism Branch, National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
Samelson
L E
LE
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D002966:Clathrin / Q000302:isolation & purification / Q000378:metabolism; D003598:Cytoskeletal Proteins; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism*; D046911:Macromolecular Substances; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D015513:Oncogene Proteins / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000032:analysis*; D010748:Phosphopeptides / Q000737:chemistry / Q000302:isolation & purification; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000737:chemistry / Q000378:metabolism; D000074405:Valosin Containing Protein; D000099149:Ezrin
D000251:Adenosine Triphosphatases; D018797:Cell Cycle Proteins; D002966:Clathrin; D003598:Cytoskeletal Proteins; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; D046911:Macromolecular Substances; D015513:Oncogene Proteins; D010455:Peptides; D010748:Phosphopeptides; D010750:Phosphoproteins; D011505:Protein-Tyrosine Kinases; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell; D010738:Type C Phospholipases; D000074405:Valosin Containing Protein; D000099149:Ezrin; C496619:Vav1 protein, mouse; C046951:valosin; C000614179:Vcp protein, mouse