RRC ID 68508
著者 van Rijk AE, Stege GJ, Bennink EJ, May A, Bloemendal H.
タイトル Nuclear staining for the small heat shock protein alphaB-crystallin colocalizes with splicing factor SC35.
ジャーナル Eur J Cell Biol
Abstract AlphaB-Crystallin has for a long time been considered a specific eye lens protein. Later on it appeared that this protein belongs to the family of the small heat shock proteins and that it occurs also extra-lenticularly in many different cell types. AlphaB-Crystallin is mainly present in the cytoplasm, but there are some indications that it might have a function in the nucleus too. However, till now its presence in the nucleus is uncertain. We therefore compared the localization of alphaB-crystallin in nine cell lines cultured under normal conditions using four different antisera. All four antisera gave a diffuse staining for alphaB-crystallin in the cytoplasm, but one of the antibodies consistently showed nuclear staining in eight of the cell types, in the form of distinct speckles. These speckles are equally pronounced in the different cell types, whether or not cytoplasmic alphaB-crystallin is present. Preabsorption of the antiserum with alphaB-crystallin abolished the staining. Furthermore we demonstrate that if only minor amounts of alphaB-crystallin are present, the protein seems to be located exclusively in the nucleus. However, in case of higher amounts of protein, alphaB-crystallin is distributed between cytoplasm and nucleus. The nuclear alphaB-crystallin exists, like the cytoplasmic alphaB-crystallin, in non-phosphorylated and phosphorylated forms, is Triton-insoluble but can be extracted by 2 M NaCl. These data suggest that alphaB-crystallin might be bound to the nuclear matrix per se or to nuclear matrix proteins via other proteins. In agreement with other nuclear matrix proteins, nuclear alphaB-crystallin staining turns diffuse upon mitosis and leaves the chromosomes unstained. Double staining experiments revealed colocalization of alphaB-crystallin with the splicing factor SC35 in nuclear speckles, suggesting a role for alphaB-crystallin in splicing or protection of the splicing machinery.
巻・号 82(7)
ページ 361-8
公開日 2003-7-1
DOI 10.1078/0171-9335-00321
PII S0171-9335(04)70307-6
PMID 12924631
MeSH 3T3 Cells Animals Blotting, Western CHO Cells Cell Nucleus / chemistry Cell Nucleus / metabolism* Cells, Cultured Cricetinae Fluorescent Antibody Technique, Indirect HeLa Cells Humans Mice Nuclear Matrix / chemistry Nuclear Matrix / metabolism Nuclear Proteins / metabolism* Rats Ribonucleoproteins* Serine-Arginine Splicing Factors Staining and Labeling / methods Tumor Cells, Cultured alpha-Crystallin B Chain / metabolism*
IF 3.025
リソース情報
ヒト・動物細胞 anti-αB-crystallin(RCB1304)