Tyrosine phosphorylation of membrane-associated tubulin in nerve growth cones enriched in pp60c-src.
The product of the c-src proto-oncogene (pp60c-src) is a tyrosine-specific protein kinase that is expressed in two phases of neural development. In post-mitotic neuronal cells undergoing terminal differentiation, pp60c-src is present at high levels in the membrane of nerve growth cones and proximal axon shafts. Membrane-associated forms of alpha- and beta-tubulin are the major phosphotyrosine-modified proteins in growth cone membranes in vivo. pp60c-src phosphorylates purified, unassembled tubulin subunits in vitro, inhibiting their ability to polymerize into microtubules. It is conceivable that tubulin phosphorylation by pp60c-src in the growth cone may regulate neurite extension by altering adhesion of cells to the substratum.
Maness
P F
PF
Department of Biochemistry, University of North Carolina School of Medicine, Chapel Hill 27599.
Matten
W T
WT
D000818:Animals; D001921:Brain / Q000196:embryology* / Q000201:enzymology; D002462:Cell Membrane / Q000378:metabolism; D005333:Fetus; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011519:Proto-Oncogenes; D051381:Rats; D014404:Tubulin / Q000378:metabolism*
D014404:Tubulin; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)