THE PHOSPHORYLATION SITES OF THE B-2 CHAIN OF BOVINE ALPHA-CRYSTALLIN
THE PHOSPHORYLATION SITES OF THE B-2 CHAIN OF BOVINE ALPHA-CRYSTALLIN
复制标题
DOI：
10.1016/0006-291x(87)91457-4
复制
发表时间：
1987-05-14
影响因子：
3.1
通讯作者：
SPECTOR, A
中科院分区：
文献类型：
--
作者：
CHIESA, R;GAWINOWICZKOLKS, MA;SPECTOR, A
牛透镜α的B2链-晶状体蛋白在环磷酸腺苷依赖性反应中被磷酸化。通过分析分离自α-胰凝乳蛋白酶的32 P-标记的胰凝乳蛋白酶肽，从器官培养物中标记的晶状体中提取晶状体蛋白，发现两个磷酸化的B2链片段，序列分析结果为Arg-Ala-Pro-Ser-Trp-Ile-Asp-Thr-Gly-Leu和Ser-Leu-Ser-Pro-Phe，分别对应于56 - 65和43 - 47位残基。通过这项工作确定B1是B2的磷酸化翻译后产物。α-β的A2和B2链都是晶体蛋白在与序列Arg-（X）-Pro-Ser相似的位点被磷酸化，这是cAMP磷酸化的不寻常位点，因为磷酸化的丝氨酸之前是脯氨酸残基。它也可能是重要的是，其他B2链磷酸化位点甚至更根本上不同于以前报道的cAMP依赖性磷酸化位点。
The B2 chain of bovine lens .alpha.-crystallin is phosphorylated in a cAMP-dependent reaction. By analysis of 32P-labelled chymotryptic peptides isolated from .alpha.-crystallin obtained from lenses labelled in organ culture, two phosphorylated B2 chain fragments were found. Sequence analysis of the fragments gave the following results: Arg-Ala-Pro-Ser-Trp-Ile-Asp-Thr-Gly-Leu and Ser-Leu-Ser-Pro-Phe corresponding to residues 56 to 65 and 43 to 47, respectively. It is established by this work that B1 is a phosphorylated post-translational product of B2. Both the A2 and B2 chains of .alpha.-crystallin are phosphorylated at a similar site with the sequence Arg-(X)-Pro-Ser. This is an unusual site for cAMP-phosphorylation since the phosphorylated serine is preceded by a proline residue. It may also be of significance that the other B2 chain phosphorylation site even more radically differs from previously reported cAMP-dependent phosphorylation sites.