Purification and cellular localization of beta2-microglobulin in the testis.
Using multiple high performance liquid chromatography (HPLC) steps, a protein of 12 kDa was purified to apparent homogeneity from rat Sertoli cell-enriched culture medium (SCCM). Partial N-terminal amino acid sequence analysis revealed a sequence of NH2-IQKTPQIQVYS which is identical to beta2-microglobulin (beta2MG) previously identified in the brain. Studies by sequential reverse transcription and polymerase chain reaction (RT-PCR) indicated that beta2MG mRNA was expressed in Sertoli but not in germ cells suggesting that Sertoli cells are the source of this protein in the seminiferous epithelium behind the blood-testis barrier. The steady-state beta2MG mRNA level in Sertoli cells cultured in vitro was not affected by either follicle stimulating hormone (FSH), testosterone, estradiol, dexamethasone or several cytokines such as interleukin-1beta (IL-1beta), interleukin 6 (IL-6), and transforming growth factor beta (TGF-beta), with the exception of interferon-gamma (INFgamma) which induced a dose-dependent stimulation of beta2MG mRNA. The possible physiological significance of this protein in the male reproductive tract is discussed.
O'Bryan
M K
MK
The Population Council, New York, New York 10021, USA.
Cheng
C Y
CY
D000375:Aging / Q000378:metabolism; D000818:Animals; D001814:Blood-Testis Barrier; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D008297:Male; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000737:chemistry* / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000302:isolation & purification*
D012333:RNA, Messenger; D001613:beta 2-Microglobulin