PTK1, a novel protein kinase required for proliferation of human melanocytes.
We have identified and characterized PTK1, a novel human non-receptor protein kinase. Partial PTK1 cDNA was initially isolated by RT-PCR from mRNA of normal human melanocytes. Northern blot hybridization detected a 3.8-kb PTK1 mRNA in all tissues and cell types studied. Nucleotide sequence analysis of a full-length PTK1 cDNA showed it to encode an 847-amino acid polypeptide with an amino-terminal SH3 domain, a kinase catalytic domain, a leucine zipper-like domain, and a carboxyl proline-rich domain. The PTK1 kinase domain contains motifs generally considered diagnostic of serine/threonine kinases but also contains amino acids highly conserved among the tyrosine kinases. This suggests that PTK1 is a serine/threonine kinase, but one very closely related to the tyrosine kinase superfamily. When normal human melanocytes were exposed to antisense PTK1 oligonucleotide, cell growth was inhibited, whereas a corresponding sense oligonucleotide had no inhibitory effect. These data indicate that PTK1 plays an important role in the proliferation of normal human melanocytes.
Ezoe
K
K
Department of Medical Genetics, University of Wisconsin, Madison 53706.
Lee
S T
ST
Strunk
K M
KM
Spritz
R A
RA
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D002455:Cell Division; D018076:DNA, Complementary; D006801:Humans; D008544:Melanocytes / Q000166:cytology* / Q000201:enzymology; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics
D018076:DNA, Complementary; D012322:RNA Precursors; D012333:RNA, Messenger; D011505:Protein-Tyrosine Kinases