TRIM21

三分模體包含蛋白質21（Tripartite motif-containing protein 21，縮寫爲TRIM21），亦作E3泛素化蛋白質連接酶TRIM21（E3 ubiquitin-protein ligase TRIM21），係一種由人類TRIM21基因編碼的蛋白質。人們已經發現了該蛋白質的可變剪切變體，但目前僅查明了其中一種在完整狀態下的性質。大部分人類組織都表達此種蛋白。

三分模體包含蛋白質21（TRIM21） Tripartite motif containing 21
兩分子TRIM21的晶體結構。其中，兩分子TRIM21C端的PRYSPRY結構域分別位於左上方和左下方。它們均與位於中央的IGHG1同質二聚體C區域結合。其中，多肽鏈的C端被渲染爲紅色，N端被渲染爲藍色
有效结构 PDB 直系同源检索：PDBe, RCSB PDB查询代码列表 2IWG
标识
代号	TRIM21; RNF81; RO52; Ro/SSA; SSA; SSA1
扩展标识	遗传学：109092 鼠基因：106657 同源基因：2365 GeneCards: TRIM21 Gene
EC編號	6.3.2.-
基因本体论描述 分子功能 · DNA binding · RNA binding · ubiquitin-protein transferase activity · protein binding · zinc ion binding · ligase activity · identical protein binding 细胞成分 · cytoplasmic mRNA processing body · nucleus · nucleoplasm · cytoplasm · cytosol · SCF ubiquitin ligase complex · ribonucleoprotein complex 生物过程 · protein polyubiquitination · protein monoubiquitination · cell cycle · protein ubiquitination · cytokine-mediated signaling pathway · protein destabilization · negative regulation of NF-kappaB transcription factor activity · regulation of type I interferon production · positive regulation of type I interferon production · negative regulation of viral transcription · innate immune response · positive regulation of cell cycle · positive regulation of viral entry into host cell · positive regulation of sequence-specific DNA binding transcription factor activity · protein autoubiquitination · interferon-gamma-mediated signaling pathway · protein trimerization · negative regulation of protein deubiquitination · negative regulation of viral release from host cell Sources: Amigo / QuickGO
RNA表达模式
更多表达数据
直系同源体
物种	人类	小鼠
Entrez	6737	20821
Ensembl	ENSG00000132109	ENSMUSG00000030966
UniProt	P19474	Q62191
mRNA序列	NM_003141	NM_001082552
蛋白序列	NP_003132	NP_001076021
基因位置	Chr 11: 4.38 – 4.39 Mb	Chr 7: 102.56 – 102.57 Mb
PubMed查询	[1]	[2]

結構

TRIM21係TRIM蛋白質家族的成員。TRIM模體包含了三個鋅結合結構域、一個環指結構域、一個1型B箱、一個2型B箱鋅指，以及一個捲曲螺旋區域。

功能

TRIM21爲一種細胞內抗體介導蛋白水解途徑的細胞內抗體效應子。它會與標記感染細胞的無包膜病毒體的抗體上的免疫球蛋白G和免疫球蛋白M相連。隨後，其自身發生泛素化或一個輔助因子發生泛素化。其後，TRIM21會負責引導病毒體到有蛋白酶的位置。抗體和病毒的衣殼會被蛋白酶水解，但TRIM21卻不會。

TRIM21爲RoSSA核糖核蛋白的一個組成成分。RoSSA還含有一條單多肽鏈以及一條小分子RNA（這條RNA有4種）。細胞質和細胞核中均有RoSSA粒子。

臨床意義

RoSSA會與乾燥綜合徵和全身性紅斑狼瘡患者體內的自身抗原反應。亦有研究者以TRIM21爲基礎研發新藥。

拓展閱讀

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