Exons lost and found. Unusual evolution of a seminal vesicle transglutaminase substrate.
The GP1G gene codes for three of the four abundant androgen-regulated secretory proteins produced by the guinea pig seminal vesicle. Sequencing of the entire 6.3-kilobase gene and comparison with other mammalian seminal vesicle secretory protein genes reveals a common three-exon, two-intron organization. However, significant sequence similarity between this group of genes is largely limited to their 5'-flanking regions and first exons, which code almost exclusively for signal peptides in each case. The first intron of GP1G does contain a region with high similarity to the coding exon of a human seminal vesicle secretory protein gene, semenogelin II. The 3' half of the GP1G gene appears to share a common ancestry with the human SKALP/elafin gene. Sequences related to the elafin promoter, coding, untranslated regions, and introns are clearly identifiable within the GP1G sequence. The elafin gene codes for a serine protease inhibitor and is expressed in a variety of different human tissues. To determine if the GP1G gene was also active outside of the seminal vesicle, RNA from a variety of guinea pig tissues was hybridized to a GP1G cDNA probe. At least three novel RNA bands hybridizing to the GP1G probe were detected in testis RNA samples, and GP1G-related mRNAs were also found in other tissues. These data suggest that these seminal vesicle secretory proteins may have functional roles outside the reproductive system.
Hagstrom
J E
JE
Department of Biochemistry and Molecular Biology, Mayo Clinic/Foundation, Rochester, Minnesota 55905, USA.
Fautsch
M P
MP
Perdok
M
M
Vrabel
A
A
Wieben
E D
ED
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004247:DNA; D005091:Exons; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D029607:Seminal Vesicle Secretory Proteins; D012669:Seminal Vesicles / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D011503:Transglutaminases / Q000378:metabolism*
D011506:Proteins; D029607:Seminal Vesicle Secretory Proteins; C101178:Svs4 protein, rat; D004247:DNA; D011503:Transglutaminases