| Abstract: |
The Hardy-Zuckerman 4 feline sarcoma virus (HZ4-FeSV), isolated from a feline fibrosarcoma, is a replication defective acute transforming feline retrovirus that originated by transduction of feline c-kit sequences with feline leukemia virus (FeLV). The v-kit sequences of the HZ4-FeSV, a segment of 1106 nucleotides, correspond to sequences of the cytoplasmic domain of the c-kit receptor kinase. The HZ4-FeSV is known to encode an 80-kilodalton protein with FeLV gag and kit determinants. The P80(gag-kit) protein and its associated activities from HZ4-FeSV-transformed mink cells were characterized. The P80(gag-kit) protein was found to be myristoylated, suggesting a membrane associated for this protein. In agreement with the predicted relationship with tyrosine kinases, by using the in vitro immune complex-kinase procedure, the P80(gag-kit) protein was shown to display a tyrosine-specific autophosphorylation activity. In vivo, the P80 protein was found to be phosphorylated on serine and threonine and to a lesser degree on tyrosine. In addition, potential in vivo protein substrates for tyrosine-specific phosphorylation mediated by the P80(gag-kit) kinase were identified in HZ4-FeSV-transformed cells. |
| Keywords: |
proto-oncogene proteins; nonhuman; animal cell; animal; protein tyrosine kinase; phosphorylation; oncogene; blotting, western; cat; cats; cell line, transformed; tyrosine kinase; retroviridae; electrophoresis, polyacrylamide gel; gene products, gag; protein-tyrosine kinase; oncogene v kit; priority journal; article; sarcoma virus; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; retroviridae proteins, oncogenic; transforming protein; proto-oncogene protein c-kit; hz4-fesv; v-kit oncogene; sarcoma viruses, feline
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