OTUB1 (D8F7) Rabbit mAb

• 产品编号：CST-3783S      品牌：CST       原厂货号：3783S
• 产品分类：抗体 > 一抗 > 蛋白特异性一抗
• 应用分类：

描述：

OTUB1 (D8F7) Rabbit mAb兔单抗识别内源性的OTUB1总蛋白。该抗体与OTUB2无交叉反应性，并且基于序列比对预测其也不与OTUB1的同源异构体2(ARF-1)发生交叉发应。此单克隆抗体经合成与人OTUB1蛋白Ile82邻近的氨基酸残基序列一致的肽段，免疫动物产生。蛋白泛素化和去泛素化作用是由泛素酶(UBEs)和去泛素酶(DUBs)催化的可逆过程(1,2)。DUBs分为5个亚家族：USP, UCH, OTU, MJD,和JAMM (1,2)。OUT亚家族包括大约100种可能的半胱氨酸蛋白酶，与果蝇的卵巢肿瘤基因产物具有同源性(3)。OTUB1和OTUB2（OUT结构域-含有Ubal-结合蛋白）与DUB并无任何相似性，但是亲近的同源物，并具有含有保守半胱氨酸和天冬氨酸残基的OUT结构域，因而具有半胱氨酸蛋白酶的催化三联体。此外，OTUB1和OTUB2的序列分析表明，Ub-相互作用模序(UIMs)和Ub-相关的结构域(UBAs)构成的蛋白，可以调节蛋白泛素化作用。OTUB1和OTUB2也具有核定位信号(NLS)和一种LxxLL模序，其可以介导转录辅激活因子和细胞核激素受体(4)。OTUB1通过选择性剪接为两种同源异构体形式；较短的31 kDa同源异构体广泛表达，而较长的35 kDa同源异构体 (ARF-1)则是限制性表达，主要在淋巴器官中被检测到(5)。生物化学分析表明，OTUB1倾向于剪切K48-连接的泛素，而非K63-连接的泛素，并能够剪切NEDD8, 而非SUMO-1, -2, 和-3 or ISG15结合物(6)。OTUB1同源异构体通过调节E3连接酶GRAIL的稳定性，参与到无能诱导的CD4+ T细胞(5)。此外最近，通过一种新的机制而非利用OTUB1 DUB活性，OTUB1被发现可以结合并抑制具有E2活性的UBE2N，因而E3连接酶RNF168可以推动泛素作用依赖的DNA双链损伤的修复(7)。OTUB1也可以抑制MDM2-依赖的泛素化作用，独立于p53的催化活性，主要通过抑制MDM2同源的E2 UbcH5的活性(8)。

1. Nijman, S.M. et al. (2005) Cell 123, 773-86.
2. Nalepa, G. et al. (2006) Nat Rev Drug Discov 5, 596-613.
3. Makarova, K.S. et al. (2000) Trends Biochem Sci 25, 50-2.
4. Balakirev, M.Y. et al. (2003) EMBO Rep 4, 517-22.
5. Soares, L. et al. (2004) Nat Immunol 5, 45-54.
6. Edelmann, M.J. et al. (2009) Biochem J 418, 379-90.
7. Nakada, S. et al. (2010) Nature 466, 941-6.
8. Sun, X.X. et al. (2012) EMBO J 31, 576-92.

原厂资料：

Specificity / Sensitivity

OTUB1 (D8F7) Rabbit mAb recognizes endogenous levels of total OTUB1 protein. This antibody does not cross-react with OTUB2 and based upon sequence alignment, is not predicted to cross-react with OTUB1, isoform 2 (ARF-1).

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Ile82 of human OTUB1 protein.

Background

Protein ubiquitination and deubiquitination are reversible processes catalyzed by ubiquitinating enzymes (UBEs) and deubiquitinating enzymes (DUBs) (1,2). DUBs are categorized into 5 subfamilies: USP, UCH, OTU, MJD, and JAMM (1,2). The OTU subfamily comprises a group of approximately 100 putative cysteine proteases that are homologous to the ovarian tumor gene product of Drosophila (3). OTUB1 and OTUB2 (OTU domain-containing Ubal-binding proteins) display no significant similarity to any known DUB, but are close homologs and possess an OTU domain that contains conserved cysteine, histidine, and aspartate residues that define the putative catalytic triad of cysteine proteases. Furthermore, sequence analysis of OTUB1 and OTUB2 reveals the presence of putative Ub-interaction motifs (UIMs) and Ub-associated domains (UBAs), which are characteristic of proteins that regulate protein ubiquitination. OTUB1 and OTUB2 also possess a putative nuclear localization signal (NLS) and a consensus LxxLL motif, which mediates the interaction between transcriptional co-activators and nuclear hormone receptors (4).

OTUB1 exists as two isoforms that are generated by alternative splicing; the shorter 31 kDa isoform is ubiquitously expressed, while the longer 35 kDa isoform (ARF-1) has a more restricted expression pattern and is mostly detected in lymphoid organs (5). Biochemical analysis has demonstrated that OTUB1 has a preference for cleaving K48-linked polyubiquitin chains over K63-linked polyubiquitin chains and is capable of cleaving NEDD8, but not SUMO-1, -2, and -3 or ISG15 conjugates (6). OTUB1 isoforms have been implicated in anergy induction in CD4+ T cells by regulating the stability of the E3 ligase GRAIL (5). More recently, OTUB1 was found to bind to and inhibit the E2 activity of UBE2N through a novel mechanism not involving OTUB1 DUB activity, thus compromising the ability of the E3 ligase RNF168 to drive ubiquitination-dependent repair of DNA double-strand lesions (7). OTUB1 also appears to suppress MDM2-dependent ubiquitination of p53 independent of its catalytic activity, primarily by suppressing the activity of the MDM2 cognate E2 UbcH5 (8).

1. Nijman, S.M. et al. (2005) Cell 123, 773-86.
2. Nalepa, G. et al. (2006) Nat Rev Drug Discov 5, 596-613.
3. Makarova, K.S. et al. (2000) Trends Biochem Sci 25, 50-2.
4. Balakirev, M.Y. et al. (2003) EMBO Rep 4, 517-22.
5. Soares, L. et al. (2004) Nat Immunol 5, 45-54.
6. Edelmann, M.J. et al. (2009) Biochem J 418, 379-90.
7. Nakada, S. et al. (2010) Nature 466, 941-6.
8. Sun, X.X. et al. (2012) EMBO J 31, 576-92.

注意事项：

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibody.