Karim M A, Ohta K, Egashira M, Jinno Y, Niikawa N, Matsuda I, Indo Y
Department of Pediatrics, Kumamoto University School of Medicine, Japan.
Genomics. 1996 Jan 15;31(2):167-76. doi: 10.1006/geno.1996.0028.
The LIM domain is present in a wide variety of proteins with diverse functions and exhibits characteristic arrangements of Cys and His residues with a novel zinc-binding motif. LIM domain proteins have been implicated in development, cell regulation, and cell structure. A LIM domain protein was identified by screening a human cDNA library with rat cysteine-rich intestinal protein (CRIP) as a probe, under conditions of low stringency. Comparison of the predicted amino acid sequence with several LIM domain proteins revealed 93% of the residues to be identical to rat LIM domain protein, termed ESP1 or CRP2. Thus, the protein is hereafter referred to as human ESP1/CRP2. The cDNA encompasses a 1171-base region, including 26, 624, and 521 bases in the 5'-noncoding region, coding region, and 3'-noncoding regions, respectively, and encodes the entire ESP1/CRP2 of 208 amino acids (M(r), 22,496). Human ESP1/CRP2 protein has two LIM domains, and each shares 35.1% and 77 or 79% identical residues with human cysteine-rich protein (CRP) and rat CRIP, respectively. Northern blot analysis of ESP1/CRP2 in various human tissues showed distinct tissue distributions compared with CRP and CRIP, suggesting that each might serve related but specific roles in tissue organization or function. Using a panel of human-rodent somatic cell hybrids, the ESP1/CRP2 locus was assigned to chromosome 14. Fluorescence in situ hybridization, using cDNA and a genome DNA fragment of the ESP1/CRP2 as probes, confirms this assignment and relegates regional localization to band 14q32.3.
LIM结构域存在于多种具有不同功能的蛋白质中，其半胱氨酸（Cys）和组氨酸（His）残基呈现出特征性排列，并具有一种新型锌结合基序。LIM结构域蛋白与发育、细胞调节及细胞结构有关。在低严谨条件下，以大鼠富含半胱氨酸的肠蛋白（CRIP）为探针筛选人cDNA文库，鉴定出一种LIM结构域蛋白。将预测的氨基酸序列与几种LIM结构域蛋白进行比较，发现93%的残基与大鼠LIM结构域蛋白相同，后者称为ESP1或CRP2。因此，该蛋白以下称为人ESP1/CRP2。该cDNA包含一个1171个碱基的区域，5'-非编码区、编码区和3'-非编码区分别包含26、624和521个碱基，编码208个氨基酸（分子量为22496）的完整ESP1/CRP2。人ESP1/CRP2蛋白有两个LIM结构域，每个结构域与人富含半胱氨酸蛋白（CRP）和大鼠CRIP分别有35.1%以及77%或79%的相同残基。对人ESP1/CRP2在各种人体组织中的Northern印迹分析表明，与CRP和CRIP相比，其组织分布不同，这表明它们在组织组成或功能方面可能发挥相关但特定的作用。利用一组人-啮齿动物体细胞杂种，将ESP1/CRP2基因座定位于14号染色体。以ESP1/CRP2的cDNA和基因组DNA片段为探针进行荧光原位杂交，证实了这一定位，并将区域定位到14q32.3带。
