Ctnnb1 - catenin (cadherin associated protein), beta 1 Gene

中文名称：连环蛋白 (钙粘蛋白相关蛋白) ， β 1

种属: Mus musculus

同用名: Bfc; Mesc; Catnb

关于 Ctnnb1

功能概要

该基因不仅编码经典钙粘蛋白粘附复合物的重要细胞质成分，该复合物在上皮细胞中形成粘附连接并介导许多其他组织中的细胞 - 细胞粘附，而且还是控制细胞生长和分化的经典 Wnt 信号通路中的关键信号分子在正常发育和肿瘤发生过程中。该基因产物包含一个中央犰狳重复结构域，通过该结构域结合经典钙粘蛋白的细胞质尾部；同时，它还结合α-连环蛋白，进一步将钙粘蛋白复合物直接或间接地连接到肌动蛋白细胞骨架。因此，β-连环蛋白对于经典钙粘蛋白的粘附功能是必需的。这种蛋白质的另一个关键功能是介导经典的 Wnt 信号通路和调节基因转录。没有 Wnt 信号，与钙粘蛋白复合物无关的细胞质 β-连环蛋白在 N 端 Ser/Thr 残基处被所谓的含有轴蛋白、腺瘤性息肉病大肠杆菌 (APC)、酪蛋白激酶 I 和 GSK3B 的降解复合物快速磷酸化，然后被 β-TrCP 泛素化，并被蛋白酶体降解。然而，在 Wnt 信号存在的情况下，降解复合物被破坏，稳定的细胞质 β-连环蛋白易位到细胞核，在那里它结合各种转录因子，并与这些因子一起调节许多下游基因的转录。该基因的突变与多种类型的肿瘤有关。已发现该基因的选择性剪接变体。 [RefSeq 提供，2009 年 9 月]

This gene encodes not only an important cytoplasmic component of the classical cadherin adhesion complex that forms the adherens junction in epithelia and mediates cell-cell adhesion in many other tissues but also a key signaling molecule in the canonical Wnt signaling pathway that controls cell growth and differentiation during both normal development and tumorigenesis. The gene product contains a central armadillo-repeat containing domain through which it binds the cytoplasmic tail of classical cadherins; meanwhile, it also binds alpha-catenin, which further links the cadherin complex to the actin Cytoskeleton either directly or indirectly. Beta-catenin is therefore necessary for the adhesive function of classical Cadherins. Another key function of this protein is to mediate the canonical Wnt signaling pathway and regulate gene transcription. Without Wnt signal, cytoplasmic beta-catenin that is not associated with the cadherin complex is quickly phosphorylated at the N-terminal Ser/Thr residues by the so called degradation complex containing axin, adenomatous polyposis coli (APC), Casein Kinase I, and GSK3B, then ubiquitylated by beta-TrCP, and degraded by the Proteasome. However, in the presence of Wnt signal, the degradation complex is disrupted and the stabilized cytoplasmic beta-catenin translocates into the nucleus, where it binds various transcription factors and, together with these factors, regulates the transcription of many downstream genes. Mutations of this gene have been linked with various types of tumors. Alternatively spliced variants have been found for this gene. [provided by RefSeq, Sep 2009]