Molecular Cloning and Sequencing of Sulfated Glycoprotein-2 cDNA from Testis of Mouse: Implications of Two Different mRNAs of SGP-2

We cloned a mouse homolog of sulfated glycoprotein-2 (SGP-2) cDNA by screening a mouse testicular cDNA library and its nucleotide sequence was determined. The predicted amino acid sequence of the cDNA shares 93 % identity with that of rat SGP-2. The nucleotide sequences of both cDNAs show extensive homology throughout the open reading frames and 3′ untranslated regions. The 5′ untranslated regions, however, share homology only up to 28 bp upstream from the start codons; the rest of sequences are quite different. DNA sequence homology search to mouse SGP-2 cDNA through the EMBL/GenBank database and a recent study on the genomic organization of rat TRPM-2 gene suggest a possibility that there are at least two different SGP-2 mRNAs as a result of alternative splicing and/or different promoter usage in mouse.