Rat testicular testibumin is identical to sulfated glycoprotein-1 (SGP-1) whose mRNA expression in the testis is age- but not germ cell-dependent.
Using sequential HPLC and capillary electrophoresis (CE), testibumin (CMB-1) has been purified to apparent homogeneity from Sertoli cell-enriched culture medium prepared from 20-day-old rat testes. N-Terminal amino acid sequence analysis of the purified testibumin revealed a partial sequence of NH2-XPVQDPKI. When this partial sequence was compared to existing protein database, it was shown that it is identical to a previously isolated Sertoli cell secretory protein, sulfated glycoprotein I (SGP-1). The fact that testibumin is equivalent to SGP-1 was further confirmed when its full-length cDNA was isolated and sequenced. Studies using quantitative PCR to examine the changes of steady-state mRNA level of testibumin (SGP-1) in the rat testes between 3 and 60 days of age indicated that its mRNA increased rapidly after birth, peaked at 10-20 days, and declined rapidly where the adult testibumin mRNA level was similar to the neonatal rat at 3 days of age. Depletion of germ cells by a single dose of lonidamine, an antispermatogenic drug, did not induce an increase in testibumin (SGP-1) mRNA level indicating its mRNA expression is not dependent on germ cells.
Mathur
P P
PP
Population Council, Center for Biomedical Research, New York, New York 10021.
Mo
M Y
MY
Panzironi
C
C
Silvestrini
B
B
Bardin
C W
CW
Grima
J
J
Cheng
C Y
CY
D000375:Aging / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000988:Antispermatogenic Agents / Q000494:pharmacology; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004586:Electrophoresis / Q000379:methods; D005786:Gene Expression Regulation; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D049231:Saposins; D012708:Sertoli Cells / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism
D000988:Antispermatogenic Agents; D018076:DNA, Complementary; D006023:Glycoproteins; D007191:Indazoles; C483347:Psap protein, rat; D012333:RNA, Messenger; D049231:Saposins; C016371:lonidamine