αB‐crystallin in the rat lens is phosphorylated at an early post‐natal age

Publisher Website
Google Scholar
Abstract
We determined the developmental changes in the phosphorylation state of αB-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 αB-crystallin. Phosphorylated forms of αB-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 αB-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 αB-crystallin, also increased in a development-dependent manner. Thus we found that the developmental increase of the phosphorylation at Ser-45 of αB-crystallin in the rat lens was due to the developmental activation of p44/42 MAP kinase.