Ito H, Iida K, Kamei K, Iwamoto I, Inaguma Y, Kato K
Department of Biochemistry, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan.
FEBS Lett. 1999 Mar 12;446(2-3):269-72. doi: 10.1016/s0014-5793(99)00242-2.
We determined the developmental changes in the phosphorylation state of alphaB-crystallin in lenses from rats at various post-natal ages by isoelectric focusing gel electrophoresis or sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a subsequent Western blot analysis of extracts of lenses using antibodies that recognized the carboxy-terminal sequence or each of the three phosphorylated serine residues (Ser-19, Ser-45 and Ser-59) in alphaB-crystallin. Phosphorylated forms of alphaB-crystallin were barely detected at birth but they became detectable at 3 weeks of age and reached plateau levels at 8 weeks of age. The phosphorylation of alphaB-crystallin at Ser-45 was observed preferentially. The active form of p44/42 MAP kinase, which is responsible for the phosphorylation of Ser-45 in alphaB-crystallin, also increased in a development-dependent manner. Thus we found that the developmental increase of the phosphorylation at Ser-45 of alphaB-crystallin in the rat lens was due to the developmental activation of p44/42 MAP kinase.
我们通过等电聚焦凝胶电泳或十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳，以及随后使用识别αB - 晶状体蛋白羧基末端序列或三个磷酸化丝氨酸残基（Ser - 19、Ser - 45和Ser - 59）中每一个的抗体对晶状体提取物进行蛋白质免疫印迹分析，确定了不同出生后年龄大鼠晶状体中αB - 晶状体蛋白磷酸化状态的发育变化。出生时几乎检测不到αB - 晶状体蛋白的磷酸化形式，但在3周龄时可检测到，8周龄时达到稳定水平。αB - 晶状体蛋白在Ser - 45处的磷酸化更为明显。负责αB - 晶状体蛋白中Ser - 45磷酸化的p44/42丝裂原活化蛋白激酶的活性形式也以发育依赖的方式增加。因此我们发现，大鼠晶状体中αB - 晶状体蛋白Ser - 45磷酸化的发育性增加是由于p44/42丝裂原活化蛋白激酶的发育性激活所致。
