The cytoskeletal protein talin is O-glycosylated

J Biol Chem. 1992 Jul 15;267(20):14424-8.

Abstract

Talin is a 215-kDa cytoskeletal protein implicated in linking actin filaments to the plasma membrane. We show here that chicken gizzard talin is galactosylated by incubation with UDP-[3H]galactose and galactosyl-transferase. The labeled carbohydrate moiety is removed by beta-elimination and comigrates with Gal beta 1-4GlcNAcitol, indicating that talin belongs to a recently discovered class of cytosolic proteins carrying N-acetylglucosamine (GlcNAc) O-linked to serine or threonine (Holt, G. D., and Hart, G. W. (1986) J. Biol. Chem. 261, 8049-8057). Two glycosylated sequences were identified in the tail domain of talin: ANQAIQMAXQNLVDPAXTQ and GILANQLTNDYGQLAQQ, corresponding to amino acids 1470-1488 and 1883-1899, respectively, of the mouse talin amino acid sequence (Rees, D. J. G., Ades, S. E., Singer, S. J., and Hynes, R. O. (1990) Nature 347, 685-689). The putative glycosylation sites are PAXTQ and QLTND. At most 6% of chicken gizzard talin and 3% of porcine stomach talin are galactosylated by galactosyltransferase. Furthermore, human platelet talin is not labeled at all by the procedure, indicating that it may not be glycosylated.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Autoradiography
  • Blood Platelets / metabolism
  • Chickens
  • Galactosyltransferases / metabolism*
  • Gastric Mucosa / metabolism
  • Gizzard, Avian / metabolism
  • Glycosylation
  • Humans
  • Mice
  • Molecular Sequence Data
  • Muscle, Smooth / metabolism
  • Sequence Homology, Nucleic Acid
  • Swine
  • Talin / chemistry*
  • Talin / isolation & purification
  • Talin / metabolism
  • Tritium
  • Uridine Diphosphate Galactose / metabolism

Substances

  • Talin
  • Tritium
  • Uridine Diphosphate Galactose
  • Galactosyltransferases