期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1991
卷号：88
期号：9
页码：3652-3656
DOI：10.1073/pnas.88.9.3652
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Sequence similarity between alpha B-crystallin and small heat shock proteins (HSPs) has prompted us to investigate whether alpha B-crystallin expression is induced by heat shock. Indeed, accumulation of alpha B-crystallin was detected immunologically in NIH 3T3 cells after incubation at elevated temperatures and after addition of Cd2+ or sodium arsenite to these cells. Two-dimensional gel electrophoresis revealed identity between alpha B-crystallin from eye lenses and from heat-treated fibroblasts. The promoter of the alpha B-crystallin gene was fused to the bacterial chloramphenicol acetyltransferase gene and was shown to confer heat inducibility on this reporter gene in transient transfection assays. A perfect heat shock element within the promoter region is likely to mediate this response. Small HSPs and alpha B-crystallin were shown to share the following two physical properties: (i) they form supramolecular structures with sedimentation values around 17 S and (ii) they are associated with the nucleus at high temperatures and are localized in the cytoplasm under normal conditions. We conclude that alpha B-crystallin has to be considered a member of the class of small HSPs.
