Alternative processing of androgen-binding protein RNA transcripts in fetal rat liver. Identification of a transcript formed by trans splicing.

摘要: Androgens and their nuclear receptor regulate genes necessary for development of the male phenotype, a process that is thought to be modulated by extracellular androgen carrier proteins. Two these proteins, testicular androgen-binding protein (ABP) plasma sex hormone-binding globulin (SHBG), are encoded same gene, but differ in glycosylation possibly amino acid sequence. To investigate ABP-SHBG gene expression fetal rat liver, we analyzed RNA transcripts expressed protein. These studies demonstrated transient ABP hepatocytes during time testosterone-dependent differentiation Wolffian duct. Analysis cDNA clones derived from liver libraries identified two cDNAs represented alternatively spliced RNAs. One had an alternate exon 1, suggesting function another promoter liver. This also lacked 6 DNA, alteration implicates regulatory functions. The other fused transcript (exons 1-5) histidine decarboxylase (HDC) encoding Mr 98,000 precursor domains were joined at splice junctions HDC genes, which localized chromosomes 10 3, respectively. Our results indicate joining was trans (donor acceptor)-splicing mechanism. Data Northern hybridization experiments suggest fusion present RNA. Polymerase chain reaction with further support existence ABP-HDC transcript, as well mRNA. Moreover, 93,000 immunoreactive transiently expression. Expression COS cells yielded activity predicted size (Mr = 93,000) on Western immunoblots.