CRYGA - crystallin gamma A Gene

中文名称：晶状体γ A

种属: Homo sapiens

同用名: CRYG1; CRYG5; CRY-g-A

关于 CRYGA

功能概要

晶状体蛋白分为两类：分类群特异性或酶类，以及普遍存在的。后一类构成脊椎动物眼睛晶状体的主要蛋白质，并维持晶状体的透明度和折射率。由于晶状体中央纤维细胞在发育过程中会失去细胞核，因此会产生这些晶状体蛋白并在整个生命过程中保留下来，从而使它们成为极其稳定的蛋白质。哺乳动物晶状体蛋白分为 alpha、beta 和 gamma 家族； beta 和 γ 晶状体蛋白也被认为是一个超家族。 Alpha 和 Beta 家族进一步分为酸性和碱性组。晶状体蛋白中存在七个蛋白质区域：四个同源基序、一个连接肽以及 N 和 C 末端延伸。 γ-晶状体蛋白是一组同质的高度对称的单体蛋白质，通常缺乏连接肽和末端延伸。它们在早期发育后受到不同的调节。四个伽马晶状体蛋白基因 (伽马-A 到伽马-D) 和三个假基因 (伽马-E、伽马-F、伽马-G) 在基因组片段中串联组织为基因簇。无论是由于衰老还是特定基因的突变，γ-晶状体蛋白都参与了白内障的形成。[RefSeq 提供，2008 年 7 月]

Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Gamma-crystallins are a homogeneous group of highly symmetrical, monomeric proteins typically lacking connecting peptides and terminal extensions. They are differentially regulated after early development. Four gamma-crystallin genes (gamma-A through gamma-D) and three pseudogenes (gamma-E, gamma-F, gamma-G) are tandemly organized in a genomic segment as a gene cluster. Whether due to aging or mutations in specific genes, gamma-crystallins have been involved in cataract formation. [provided by RefSeq, Jul 2008]