αB-Crystallin phosphorylated at Ser-59 is localized in centrosomes and midbodies during mitosis

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• 作者：Yutaka Inaguma ; Hidenori Ito ; Ikuko Iwamoto ; Shinsuke Saga ; Kanefusa Kato
• 关键词：α ; B-crystallin ; centrosomes ; midbodies
• 刊名：European Journal of Cell Biology
• 出版年：2001
• 出版时间：December 2001
• 年：2001
• 卷：80
• 期：12
• 页码：741-748
• 全文大小：240 K

文摘

We have reported that the three serine residues in αB-crystallin are phosphorylated under various stress conditions. We prepared affinity-purified antibodies recognizing each of the phosphorylated serine residues (Ser-19, Ser-45, and Ser-59, respectively) in αB-crystallin with peptides (p19S, p45S, or p59S) that contained the corresponding phosphorylated serine residue. Immunocytochemically anti-p45S antibodies stained the cytoplasm of mitotic cells (J. Biol. Chem. 273, 28 346 – 28 354). We have now found that the anti-p59S antibodies recognize centrosomes and midbodies of dividing cells. αB-Crystallin was the only protein recognized by the anti-p59S antibodies in Western blot analyses of isolated centrosome fractions. αB-Crystallin phosphorylated at Ser-59 was localized at the microtubule organizing centers by means of double staining with anti-β-tubulin antibody in aster formation analysis and was co-localized with γ-tubulin in centrosomes. γ-Tubulin was co-immunoprecipitated with αB-crystallin in U373 glioma cell extracts. On the other hand, the location of the phosphorylated αB-crystallin deviated from that of α-tubulin or γ-tubulin in the midbody region. Taken together with the evidences that several chaperones are distributed to centrosomes, these results suggest that αB-crystallin as a chaperone might be also involved in the quality control of proteins.