RBM4 Q9BWF3

RNA结合蛋白4 (Lark同源物) (hLark) (RNA基序结合蛋白4) (RNA基序结合蛋白4a)

功能描述

RNA结合因子，参与多种细胞过程，如pre-mRNA的可变剪接和翻译调控。调节可变5'-剪接位点和外显子选择。作为肌细胞分化促进因子。在肌细胞分化过程中激活PTB pre-mRNA的外显子跳跃。拮抗剪接因子PTBP1的活性，以调节原肌球蛋白alpha亚型的肌细胞特异性外显子选择。结合TPM1和MAPT pre-mRNA的内含子富嘧啶序列。响应生物钟所需，用于PER1 mRNA的翻译激活。直接结合PER1 mRNA的3'-UTR。通过结合mRNA 3'UTR内的CU富集反应元件，对Cap依赖性翻译施加抑制活性，该过程在应激条件下或肌细胞分化期间增强。招募EIF4A1以响应细胞应激刺激IRES依赖性翻译起始。在应激条件下与靶mRNA种类中的内部核糖体进入片段（IRES）结合。通过促进含AGO2的miRNP与其同源靶mRNA的结合，在miRNA引导的RNA切割和翻译抑制中发挥作用。在肌细胞分化过程中与miRNAs结合。在体外优先结合5'-CGCGCG[GCA]-3'基序。 {ECO:0000269|PubMed:12628928, ECO:0000269|PubMed:16260624, ECO:0000269|PubMed:16777844, ECO:0000269|PubMed:16934801, ECO:0000269|PubMed:17284590, ECO:0000269|PubMed:17932509, ECO:0000269|PubMed:19801630, ECO:0000269|PubMed:21343338, ECO:0000269|PubMed:21518792, ECO:0000269|PubMed:37548402}.

组织特异性

Expressed in the cerebellum. Expressed in neurons and glial cells, including layers II neurons in the frontal cortex and CA1 pyramidal neurons in the hippocampus. Expressed in heart, liver, pancreas, skeletal muscle, placenta, primary fibroblasts and peripheral blood monocytes (at protein level). Ubiquitously expressed. Highly expressed in heart, placenta and skeletal muscle. Weakly expressed in pancreas, kidney, liver, lung and brain.

亚细胞定位

Nucleus. Nucleus, nucleolus. Nucleus speckle. Cytoplasm. Cytoplasmic granule. Note=Undergoes continuous nucleocytoplasmic shuttling. Upon nuclear import colocalizes with SR proteins in nuclear speckles. Arsenite stress-induced phosphorylation increases its subcellular relocalization from the nucleus to the cytoplasm and to cytoplasmic stress granules (SG) via a p38 MAPK signaling pathway. Primarily localized in nucleus and nucleoli under cell growth conditions and accumulated in the cytoplasm and cytoplasm perinuclear granules upon muscle cell differentiation.