Study Of A Novel Serine/Threonine Protein Kinase Clone And Its Primary Biological Function

Protein kinases play a key role in cell growth regulation. We have isolated a cDNA fragment from a human fetal liver cDNA library. Nucleotides sequence analysis indicated this cDNA encodes a novel putative non-receptor type of serine / threonine kinase. This gene encodes a 4.0kb mRNA and are abundant in young proliferating tissues and greatly reduced in terminally differentiated tissues, this gene also was expressed at high level in several tumor cell lines, including HepG2, KB, GLC-82, Hep2, SMMC-7721 and 7402 cells. Northern blot analysis with human 1.9kb cDNA as probe showed that this gene was expressed in the normal rat liver at low level and that dramatically increased in regenerating liver after partial hepatectomied rat. A high expression of the gene was found in the rat hepatocytes induced by HGF and Insulin. Those results indicated this novel serine/threonine kinase may be involved in cell proliferation regulation.