有机阳离子/肉碱转运蛋白2 (高亲和力钠依赖性肉碱共转运蛋白) (溶质载体家族22成员5)
有机阳离子/肉碱转运蛋白2 (高亲和力钠依赖性肉碱共转运蛋白) (溶质载体家族22成员5)
O76082功能描述
钠离子依赖性、高亲和力肉碱转运蛋白。参与肉碱的主动细胞摄取。以1:1的比例转运一个钠离子和一个肉碱分子 (PubMed:10454528, PubMed:10525100, PubMed:10966938, PubMed:17509700, PubMed:20722056, PubMed:33124720)。亦转运有机阳离子，如四乙基铵 (TEA)，且不依赖钠离子。肉碱与TEA的相对摄取活性比为11.3 (PubMed:10454528, PubMed:10525100, PubMed:10966938)。在肠上皮中，转运来自枯草芽孢杆菌的群体感应五肽CSF (competence and sporulation factor)，该肽诱导细胞保护性热休克蛋白，从而促进肠道稳态 (PubMed:18005709)。可能也有助于调节血睾屏障中睾丸内有机化合物的转运 (Probable)。 {ECO:0000269|PubMed:10454528, ECO:0000269|PubMed:10525100, ECO:0000269|PubMed:10966938, ECO:0000269|PubMed:17509700, ECO:0000269|PubMed:18005709, ECO:0000269|PubMed:20722056, ECO:0000305|PubMed:35307651}.; FUNCTION: [Isoform 3]: 滞留在内质网中，无法执行肉碱摄取。 {ECO:0000269|PubMed:17509700}.
组织特异性
Strongly expressed in kidney, skeletal muscle, heart and placenta (PubMed:10454528). Primarily expressed by surface epithelial cells of the colon (at protein level) (PubMed:18005709). Expressed in CD68 macrophage and CD43 T-cells but not in CD20 B-cells (PubMed:10454528). In testis, localized to Sertoli cell basal membranes, peritubular myoid cells and Leydig cells (PubMed:35307651).
亚细胞定位
Cell membrane
关键词