title: Comparative studies of a new subfamily of human Ste20-like kinases: homodimerization, subcellular localization, and selective activation of MKK3 and p38.
abstract: The Sterile-20 or Ste20 family of serine/threonine kinases is a group of signaling molecules whose physiological roles within mammalian cells are just starting to be elucidated. Here, in this report we present the characterization of three human Ste20-like kinases with greater than 90% similarity within their catalytic domains that define a novel subfamily of Ste20s. Members of this kinase family include rat thousand and one (TAO1) and chicken KFC (kinase from chicken). For the lack of a consensus nomenclature in the literature, in this report, we shall call this family hKFC (for their homology to chicken KFC) and the three members hKFC-A, hKFC-B, and hKFC-C, respectively. These kinases have many similarities including an aminoterminal kinase domain, a serine-rich region, and a coiled-coil configuration within the C-terminus. All three kinases are able to activate the p38 MAP kinase pathway through the specific activation of the upstream MKK3 kinase. We also offer evidence, both theoretical and biochemical, showing that these kinases can undergo self-association. Despite these similarities, these kinases differ in tissue distribution, apparent subcellular localization, and feature structural differences largely within the carboxyl-terminal sequence.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D019281:Dimerization; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D019169:Jurkat Cells; D048371:MAP Kinase Kinase 3; D020930:MAP Kinase Kinase Kinases; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000201:enzymology; D014018:Tissue Distribution; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D029701:Saccharomyces cerevisiae Proteins; C117090:MAP4K4 protein, human; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; C078754:STE20 protein, S cerevisiae; D048371:MAP Kinase Kinase 3; C482530:MAP2K3 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases