摘要
JARID1C是高度保守的ARID蛋白家族的成员,该家族的蛋白参与并引起一系列生物学效应,如染色质重塑、细胞增殖与分裂、个体发育以及基因转录调控。JARID1C在人脑中表达丰富,对脑的发育和维持正常功能具有重要作用,突变可引起智力迟钝。本研究采用电子克隆(insilicocloning)的方法并结合5′末端快速扩增技术(RACE),从猪卵巢中克隆到JARID1C的全长cDNA序列(GenBank登录号:EF139241)。猪JARID1C基因的cDNA全长5,908bp,包括4,551bp的开放阅读框(ORF)、522bp的5′非翻译区(5′UTR)和835bp的3′非翻译区(3′UTR),polyA加尾信号序列AATAAA位于5,881bp和5,886bp之间。生物信息学分析揭示JARID1C蛋白含有1517个氨基酸残基,定位于细胞核中,该蛋白含有5个保守的结构域:JmjN结构域、ARID结构域、JmjC结构域、C5HC2锌指结构域和PHD锌指结构域。应用ClusterW程序分别对猪、狗、小鼠、大鼠、人和猿的JARID1C核苷酸序列和氨基酸序列进行多重序列比对,发现猪的JARID1C与其他哺乳动物具有很高的相似性。借助Mega3.1软件,采用N-J算法构建JARID1亚家族蛋白的系统进化树,揭示不同物种的进化关系。应用实时荧光定量PCR技术分析该基因在不同组织的表达差异,结果表明该基因在各组织均不同程度地表达,其中在肺和骨骼肌表达水平最低,而在脑和性腺表达水平最高。
Jumonji, AT-rich interactive domain 1C （JARID1C） protein belongs to the highly conserved ARID protein family, which is involved in chromatin remodeling and transcriptional regulation during cell growth, differentiation, and development. In humans, this gene plays a vital role in normal brain development and function. Using an in silico approach in combination with 5＇ rapid amplification of cDNA ends （5＇ RACE）, the full-length cDNA of JARIDIC （GenBank accession No. EF139241） from porcine ovary, which contains 5,908 bp nucleotides, with an open reading frame （ORF） of 4,548 bp, has been cloned. The putative porcine JARID 1C protein, which is located in the nucleus, encodes 1,516 amino acids with a molecular weight of 170 kDa and a pI of 5.44. Bioinformatic prediction indicates that the protein contains several conserved domains： a JmjN domain, an ARID domain, a JmjC domain, a C5HC2 zinc finger domain, and a PHD zinc finger domain. Similarity comparisons for nucleic and amino acid sequences reveal that the porcine JARID1C protein shares a high identity with its dog, mouse, rat, and human counterparts. The phylogenetic tree of the JARID1 subfamily proteins has been constructed to reveal the evolutionary relationship of various species. Real-time PCR analysis shows that the JARIDIC gene is expressed in various tissues, but at different levels. The expression levels of this gene are higher in the brain and gonad than in other tissues, suggesting that the JARID1C protein plays a role in porcine brain and gonad functions.
基金
the National High Technology Development Program of China (No. 2006AA10Z136).
