Zhang H, Somerville C
DOE Plant Research Laboratory, Michigan State University, East Lansing 48824.
Arch Biochem Biophys. 1990 Aug 1;280(2):412-5. doi: 10.1016/0003-9861(90)90350-8.
In order to determine the relationship of the soluble cytochrome b5 found in erythrocytes to the membrane-bound form found in other tissues, a cDNA clone encoding cytochrome b5 in chicken erythrocytes was isolated by using mixed oligonucleotides based on a partial amino acid sequence of the protein. Complete nucleotide sequence identity between the erythrocyte cDNA and the sequence of a cDNA clone of the liver protein suggests that they are transcribed from the same gene. The isolation and structural analysis of genomic clones was also consistent with the presence of only one cytochrome b5 gene in chicken. These results suggest that the formation of soluble erythrocyte cytochrome b5 occurs by proteolytic processing of the membrane-bound form. Thus, previous reports indicating that the carboxyl terminal amino acid residue of the erythrocyte form differs from the corresponding residue of the membrane-bound form may suggest the existence of a novel post-translational modification.
为了确定红细胞中发现的可溶性细胞色素b5与其他组织中发现的膜结合形式之间的关系，通过使用基于该蛋白质部分氨基酸序列的混合寡核苷酸，分离出了编码鸡红细胞中细胞色素b5的cDNA克隆。红细胞cDNA与肝脏蛋白质cDNA克隆序列之间的完全核苷酸序列一致性表明它们是从同一基因转录而来的。基因组克隆的分离和结构分析也与鸡中仅存在一个细胞色素b5基因相一致。这些结果表明，可溶性红细胞细胞色素b5的形成是通过膜结合形式的蛋白水解加工发生的。因此，先前的报道表明红细胞形式的羧基末端氨基酸残基与膜结合形式的相应残基不同，这可能暗示存在一种新的翻译后修饰。
