ABSTRACT
The 27-kDa human heat shock protein (hsp27) is dually regulated by both estrogen and heat shock treatment. Its function is obscure, but the high degree of homology to the lens alpha-crystallins and to the small heat shock proteins of Drosophila suggests that it may serve a structural function. There are at least three related human hsp27 sequences. To provide possible insight into the dual regulation of hsp27, we have determined the chromosomal location of all these and found them to be on separate chromosomes: 3, 9, and X.
Subject(s)
Chromosome Mapping , Chromosomes, Human, Pair 3 , Chromosomes, Human, Pair 9 , Heat-Shock Proteins/genetics , Multigene Family , X Chromosome , Animals , Blotting, Southern , Cricetinae , DNA Probes , DNA Restriction Enzymes , Humans , Hybrid Cells , MiceABSTRACT
The amidated decapeptide neuromedin B (NMB) is the mammalian homolog of the amphibian bombesin-like peptide ranatensin. cDNAs encoding human neuromedin B and amphibian ranatensin were isolated from human hypothalamic and Rana pipiens skin libraries, respectively. Sequence analysis revealed that NMB is encoded in a 76-amino acid precursor and ranatensin in an 82-amino acid precursor. In the NMB preprohormone, the sequence of the large form of NMB (NMB-22) immediately follows the signal peptide and is, in turn, followed by a dibasic cleavage site and a 17-amino acid carboxyl-terminal extension peptide. The structure for the ranatensin preprohormone is very similar. RNA blot analysis shows two NMB mRNA species, each approximately 800 bases, with wide distribution in brain and gastrointestinal tract. Genomic DNA blot analysis is consistent with a single human NMB gene. Analysis of mouse-human somatic cell hybrids indicates that this gene is localized on the long arm of human chromosome 15. Since the gene for human gastrin-releasing peptide is on chromosome 18, this analysis demonstrates that the bombesin-like peptide genes are not clustered.
