title: Blackjack, a novel protein associated with microtubules in embryonic neurons.
abstract: Microtubule-associated proteins can influence the organization, stability and dynamics of microtubules. We characterize a novel protein that associates with microtubules as assessed by immunofluorescence, immunoelectron microscopy, and co-sedimentation. The protein is expressed heavily in embryonic neurons and, to a lesser extent, in epithelial and mesodermal cells. The cDNA sequence predicts a protein of 1,547 amino acids and approximately 170 kDa. Immunoblot of embryo lysate demonstrates bands of approximately 240 and 260 kDa. The predicted amino acid sequence contains 77 potential serine/threonine phosphorylation sites. A distinctive feature is a predicted alpha-helical central domain comprising 21 identical repeats of an 11 amino acid sequence (PLEELRKDAAE). The protein is thermostable and has two major charge-domains: the amino-terminal 80% has an estimated pI of 4.0 and the carboxy-terminal 20%, a pI of 12.2. The protein shares several general biochemical and molecular features of MAPs, but its sequence is not similar to that of any described MAP.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Zachow
authors.forename: D
authors.initials: D
authors.lastname: Bentley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000378:metabolism; D001483:Base Sequence; D019556:COS Cells; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D006110:Grasshoppers / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D019476:Insect Proteins; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D009474:Neurons / Q000276:immunology / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D014162:Transfection
chemical_list: D000941:Antigens; D018076:DNA, Complementary; D019476:Insect Proteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; C104109:blackjack protein, Schistocerca americana