Regulated expression of intrinsic factor-cobalamin receptor by rat visceral yolk sac and placental membranes.
Regulated expression of intrinsic factor-cobalamin receptor by rat visceral yolk sac and placental membranes.
复制标题
大鼠内脏卵黄囊和胎盘膜调节内因子钴胺素受体的表达。
DOI：
10.1016/0005-2736(93)90362-4
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Seetharam,B
中科院分区：
文献类型：
--
作者：
Ramanujam,KS;Seetharam,S;Seetharam,B
Intrinsic factor-cobalamin receptor (IFCR) activity in visceral yolk sac and placental membranes is regulated during pregnancy in rats. While the IFCR activity declined in the visceral yolk sac membranes by 15-fold, it rose nearly 20-fold in the placental membranes from fourteen to nineteen days of gestation. The visceral yolk sac membranes revealed a 230 kDa protein that co-migrated with pure rat renal IFCR. This 230 kDa band was also identified as IFCR in both the membranes by immunoblotting with anti-serum to rat renal IFCR. Immunoprecipitation of35S labeled proteins obtained from in vitro translation using visceral yolk sac mRNA from 14-day pregnant rats, yielded on SDS-PAGE a single band of 220 kDa, while those obtained from 19-day pregnant rats did not. The binding of intrinsic factor-cyanol[57Co]cobalamin complex to the visceral yolk sac membranes was inhibited by princubation of these membranes with anti-serum to rat IFCR but not with anti-serum to rat asialoglycoprotein receptor or mannose or mannan orN-acetylglucosamine. Based on these results, we suggest that the IFCR activity, protein expression and mRNA levels in fetal membranes are regulated during pregnancy and may play an important role in the maternal-fetal transfer of cobalamin.
