J. Biol. Chem., Vol. 259, Issue 21, 13131-13138, 11, 1984

Analysis of a major human chorionic somatomammotropin gene. Evidence for two functional promoter elements

MJ Selby, A Barta, JD Baxter, GI Bell and NL Eberhardt

The sequence of one of the two major expressed human chorionic somatomammotropin genes (hCS-1) was determined. The hCS-1 gene and the human growth hormone gene (hGH-1) share 92% nucleotide sequence homology in their 5'- and 3'-flanking regions, introns and exons. This finding, in addition to the existence of multiple closely linked hGH and hCS genes, suggests that these genes are evolving by concerted mechanisms. S1 nuclease, hybridization, and primer extension analysis of placental poly(A+) RNA demonstrated the presence of two functional initiation sites within the hCS-1 and/or the hCS-2 gene(s). The majority (about 95%) of the transcripts initiate 30 nucleotides downstream from the TATAAA sequence, and about 5% of the transcripts initiate 30 nucleotides downstream from a CATAAA sequence located 55 nucleotides 5' to the TATAAA sequence. The presence of two functional promoter elements as well as direct repeated sequences flanking the TATAAA sequence and exon I of the hCS genes are consistent with the hypothesis (Cooke, N. E., and Baxter, J. D. (1982) Nature (Lond.) 297, 603-606) that an important regulatory element may have been inserted into the gene in a separate evolutionary event. An analysis of other direct repeats, internal homology, and homology between other growth hormone and chorionic somatomammotropin genes offers a more extensive conceptualization of how this gene family evolved.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				S.-W. Jiang, A. R. Shepard, and N. L. Eberhardt An Initiator Element Is Required for Maximal Human Chorionic Somatomammotropin Gene Promoter and Enhancer Function J. Biol. Chem., February 24, 1995; 270(8): 3683 - 3692. [Abstract] [Full Text] [PDF]

				T Lufkin and C Bancroft Identification by cell fusion of gene sequences that interact with positive trans-acting factors Science, July 17, 1987; 237(4812): 283 - 286. [Abstract] [PDF]