A cyclin-dependent kinase homologue, p130PITSLRE is a phosphotyrosine-independent SH2 ligand.
Src-homology 2 (SH2) domains are conserved, globular protein modules that mediate assembly of multicomponent signaling complexes. Phosphoproteins from the B-lymphoid cell line A20 were isolated by SH2 affinity chromatography; the peptide sequence from one of these proteins was used to molecularly clone several related complementary DNAs whose predominant protein product, p130PITSLRE, is an abundant serine/threonine kinase with ubiquitous expression in murine tissues. The sequence of a previously described cyclin-dependent kinase homologue, p58clk-1, is entirely contained within the p130PITSLRE sequence. Specific binding of p130PITSLRE to SH2 domains is mediated by a serine- and glutamic acid-rich cluster of amino acids in the N-terminal region. This interaction is dependent on serine/threonine phosphorylation but independent of tyrosine phosphorylation. Binding is inhibited by free phosphotyrosine and by a phosphotyrosine-containing peptide from polyoma middle T antigen, suggesting that the p130PITSLRE binding site in the SH2 domain overlaps the region that binds phosphotyrosine-containing peptides. Bacterially expressed p130PITSLRE fragments acquire the ability to bind an SH2 domain when phosphorylated in vitro with casein kinase II. A subset of casein kinase II phosphorylation sites may therefore constitute a phosphotyrosine-independent class of SH2 ligands.
Malek
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Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D047388:Casein Kinases; D002460:Cell Line; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D018076:DNA, Complementary; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D010766:Phosphorylation; D019000:Phosphotyrosine; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D018076:DNA, Complementary; D008024:Ligands; D019000:Phosphotyrosine; D018698:Glutamic Acid; D014443:Tyrosine; D012694:Serine; D012313:RNA; D011494:Protein Kinases; D016392:Proto-Oncogene Proteins pp60(c-src); D047388:Casein Kinases; D017346:Protein Serine-Threonine Kinases; C501852:Cdk11b protein, mouse