Molecular characterization of a germ-cell-specific antigen, TEX101, from mouse testis.
TEX101, a glycoprotein we recently identified, is primarily characterized as a unique germ-cell-specific marker protein that shows sexually dimorphic expression during mouse gonad development. Based on data obtained from molecular biological as well as immuno-morphological studies, we believe this molecule may play a role in the process underlying germ cell formation. However, many points remain unclear as the molecular characteristics and its physiological functions are far from being completely understood. To clarify the molecular basis of TEX101, we herein report a further biochemical characterization of the molecule using testicular Triton X-100 extracts from mice. Deglycosylation studies using endoglycohydrolases that delete N-linked oligosaccharides (OS) from the molecule show that TEX101 is highly (approximately 47%) N-glycosylated. All potential N-glycosylation sites within TEX101 are glycosylated and most of these sites are occupied by endoglycosidase F2-sensitive biantennary complex type OS units. In addition, an extremely low population among TEX101 possesses only endoglycosidase H-sensitive hybrid type OS units. In studies using phosphatidylinositol-specific phospholipase C against native testicular cells or TEX101 transfectant, the enzyme treatment caused major reduction of the TEX101 expression on the cell, suggesting that TEX101, at least in part, is expressed as a glycosylphosphatidylinositol-anchored protein. Taken together, these findings will help elucidate the molecular nature of TEX101, a marker molecule that appeared on germ cells during gametogenesis.
Jin
Hong
H
Institute for Environmental & Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba 279-0021, Japan.
Yoshitake
Hiroshi
H
Tsukamoto
Hiroki
H
Takahashi
Mai
M
Mori
Miki
M
Takizawa
Toshihiro
T
Takamori
Kenji
K
Ogawa
Hideoki
H
Kinoshita
Katsuyuki
K
Araki
Yoshihiko
Y
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000954:Antigens, Surface / Q000737:chemistry*; D002460:Cell Line; D004586:Electrophoresis; D058851:GPI-Linked Proteins; D006031:Glycosylation; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D013094:Spermatozoa / Q000737:chemistry / Q000276:immunology*; D013737:Testis / Q000737:chemistry / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D058851:GPI-Linked Proteins; C426726:TEX101 protein, mouse