人膀胱癌相关蛋白基因及其编码蛋白质的结构及功能预测

Structural and Functional Prediction of BLCAP Gene and Its Encoded Protein

目的 :预测人宫颈癌候选抑癌基因———膀胱癌相关蛋白 (BLCAP)基因及其编码蛋白质的结构及功能。方法 :将克隆有全长BLCAP基因的 pLXSN BLCAP质粒测序后 ,采用生物信息学的方法对其在核酸及氨基酸水平上进行分析 ,并对其编码的蛋白质的功能做了初步预测。结果 :发现了几条与BLCAP基因同源性较高的基因 :Ho mosapiensmRNA(DKFZp5 6 4M0 5 3) ,BC 1 0基因等 ,它们与BLCAP基因的序列相似性分别为 :99%和 87% ,而且不同种属间BLCAP基因较为保守。BLCAP基因编码的 87个氨基酸中亮氨酸 (1 9.5 % )、脯氨酸 (9.1 9% )、丝氨酸 (8.0 4 % )、半胱氨酸 (8.0 4 % )含量较高 ,对其二级结构的分析发现BLCAP基因编码蛋白N端以螺旋结构为主 ,C端以折叠结构为主 ,亲水性较高 ,而中间区域则以无规则卷曲为主 ,疏水性较高。在其 4 5aa～ 6 5aa处存在一个跨膜区 ,在 5 9aa～ 6 6aa处可能存在一个裂解位点 ,在 6 8位的Tyr,73位和 78位的Ser存在着 3个可能的磷酸化位点 ,且在78aa～ 81aa处发现一个典型的 [ST] X(2 ) [DE]结构 ,即酪氨酸蛋白激酶Ⅱ磷酸化位点。结论 :初步预测BLCAP基因为一个调节细胞生长的看家基因 ,其编码的蛋白质为一个Ⅰ型跨膜蛋白 。

Objective: To predict the structure and function of Homo sapiens bladder cancer associated protein (BLCAP) gene and its encoded protein. Methods:BLCAP gene was analyzed by bioinformaticd methods on nucleic acid level and amino acid level, and the structure and function of its encoded protein was predicted. Results: There were several genes that were highly resemble with BLCAP. The comparability between the sequences of BLCAP and Homo sapiens mRNA (DKFZp564M053) or BC10 was 99% and 87% respectively. The protein encoded by BLCAP consisted of Leu(19.5%),Pro(9.19%),Ser(8.04%),Cys(8.04%) and other amino acids. The se cond structure of the N terminal of BLCAP encoded protein was an alpha helix. In the C terminal, it was beta sheet and in the middle, it was coil. The terminals was more hydrophobile than the middle region. Between 45aa～55aa, there was a transmembrane region. By analyzing the signal peptide and the procedure of BLCAP gene with the program of SignalP (V1.1), a cleavage site was found in 59aa～66aa. By using the program of Netpho, we predicted there might be three phospholate sites at 68aa, 73aa and 78aa. At 78aa～81aa, a typical [ST] X (2) [DE] structure—the phospholate site of Tyrosine protein kinase was found. Conclusion: Basing on the results, we forecast that BLCAP gene regulates the growth of cells. The protein edcoded by BLCAP gene is a member of transmembrane protein Ⅰ, and the phospholate site of Tyrosine protein kinase might be related to the regulation of its functioni.