Cloning and characterization of CIS 1b (cytokine inducible SH2-containing protein 1b), an alternative splicing form of CIS 1 gene.

JAK-STAT pathway is essential in relaying cytokine signals and plays a vital role in cellular responses such as proliferation, differentiation and immunity. Some members of a recently found citokine-inducible SH2 protein (CIS, =SOCS or SSI) family have proved to have negative effects on modulating JAK-STAT signaling pathway. In the present study, a novel human cDNA (ClSlb) which proved to be a variant of CIS1 gene was isolated by screen human placenta λ gtll cDNA library and 5′-rapid amplification of cDNA ends (RACE). Furthermore, the gene structure of CIS1 was determined by comparing the cDNA sequences of Cis1 and ClSlb to the genomic sequence in human chromosome 3p21.3. The expression patterns of ClSlb as well as C1Sl were analysed by Northern blot.