Department of Animal Sciences, The Ohio State University/Ohio Agricultural Research and Development Center, Wooster, OH 44691, USA.
Reprod Biol Endocrinol. 2010 Aug 3;8:94. doi: 10.1186/1477-7827-8-94.
The endoplasmic reticulum (ER) is a major site of protein synthesis and facilitates the folding and assembly of newly synthesized proteins. Misfolded proteins are retrotranslocated across the ER membrane and destroyed at the proteasome. DERL1 is an important protein involved in the retrotranslocation and degradation of a subset of misfolded proteins from the ER. We characterized a 2617 bp cDNA from bovine granulosa cells that corresponded to bovine DERL1. Two transcripts of 3 and 2.6 kb were detected by Northern blot analysis, and showed variations in expression among tissues. During follicular development, DERL1 expression was greater in day 5 dominant follicles compared to small follicles, ovulatory follicles, or corpus luteum (CL). Within the CL, DERL1 mRNA expression was intermediate in midcycle, and lowest in late cycle as compared to early in the estrous cycle. Western blot analyses demonstrated the presence of DERL1 in the bovine CL at days 5, 11, and 18 of the estrous cycle. Co-immunoprecipitation using luteal tissues showed that DERL1 interacts with class I MHC but not with VIMP or p97 ATPase. The interaction between DERL1 and MHC I suggests that, in the CL, DERL1 may regulate the integrity of MHC I molecules that are transported to the ER membrane. Furthermore, the greater expression of DERL1 mRNA is associated with the active follicular development and early luteal stages, suggesting a role of DERL1 in tissue remodeling events and maintenance of function in reproductive tissues.
内质网（ER）是蛋白质合成的主要场所，并促进新合成蛋白质的折叠和组装。错误折叠的蛋白质被逆向转运穿过 ER 膜，并在蛋白酶体中被破坏。DERL1 是一种重要的蛋白质，参与从 ER 逆向转运和降解一组错误折叠的蛋白质。我们从牛颗粒细胞中鉴定出一个 2617bp 的 cDNA，它对应于牛 DERL1。Northern blot 分析检测到 3kb 和 2.6kb 的两种转录本，并且在组织中表现出表达的变化。在卵泡发育过程中，与小卵泡、排卵卵泡或黄体（CL）相比，天 5 的优势卵泡中 DERL1 的表达更高。在 CL 中，与发情周期的早期相比，中期 DERL1mRNA 的表达居中，而在周期晚期则最低。Western blot 分析表明，在发情周期的第 5、11 和 18 天，牛 CL 中存在 DERL1。使用黄体组织进行的共免疫沉淀表明，DERL1 与 I 类 MHC 相互作用，但不与 VIMP 或 p97ATP 酶相互作用。DERL1 与 MHC I 之间的相互作用表明，在 CL 中，DERL1 可能调节运输到 ER 膜的 MHC I 分子的完整性。此外，DERL1mRNA 的更高表达与活跃的卵泡发育和早期黄体阶段相关，这表明 DERL1 在组织重塑事件和生殖组织的功能维持中发挥作用。
