cDNA sequence and structure of a gene encoding trout testis high-mobility-group-1 protein.
Perchloric acid extraction of trout testis nuclei revealed the presence of two large high-mobility-group (HMG) proteins, HMG-T1 and HMG-T2. The sequence of a complete cDNA (1407 bp) for trout testis HMG-1 protein (referred as to HMG-T1) has been determined. The deduced HMG-T1 protein contains 203 amino acids with more than 86% similarity to mammalian HMG-1 proteins. A single-sized mRNA for HMG-T1 has been detected by Northern-blot analysis consistent with the size derived from the HMG-T1 cDNA. Amplification of human and trout genomic DNAs by polymerase chain reaction using primers specific for trout and human HMG-1 cDNAs revealed that unlike the human genome, which contains predominantly intronless HMG-1 sequences, intronless HMG-T1 sequences were not found in the fish genome. Southern-blot analysis suggested that the trout testis HMG-1 gene is encoded by at least two sequences with high similarity. A gene encoding HMG-T1 protein has been isolated from a trout testis genomic library and by PCR of trout genomic DNA (3879 bp). The trout testis HMG-1 gene is organized into five exons (four exons corresponding to the protein-coding region) and its exon/intron boundaries are identical to those of the human HMG-2 gene [Shirakawa, H. & Yoshida, M. (1992). J. Biol. Chem. 267, 6641-6645] suggesting the evolution of HMG-1 and HMG-2 genes from a common ancestor.
Department of Medical Biochemistry, University of Calgary, Canada.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus; D004247:DNA / Q000302:isolation & purification*; D005091:Exons; D006609:High Mobility Group Proteins / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D007438:Introns; D008297:Male; D008969:Molecular Sequence Data; D009710:Nucleotide Mapping; D012333:RNA, Messenger / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000737:chemistry*; D014337:Trout
D006609:High Mobility Group Proteins; D012333:RNA, Messenger; D004247:DNA