Association of NASP with HSP90 in mouse spermatogenic cells - Stimulation of ATPase activity and transport of linker histones into nuclei
Association of NASP with HSP90 in mouse spermatogenic cells - Stimulation of ATPase activity and transport of linker histones into nuclei
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DOI：
10.1074/jbc.m410397200
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发表时间：
2005-01-28
影响因子：
4.8
通讯作者：
O'Rand, MG
中科院分区：
文献类型：
--
作者：
Alekseev, OM;Widgren, EE;O'Rand, MG
NASP（核自身抗原精子蛋白）是在所有分裂细胞中发现的接头组蛋白结合蛋白，其受细胞周期调节（Richardson，R. T.，巴托瓦岛N.，Widgren，E. E、郑湖，澳-地YL，Whitfield，M.，Marzluff，W. F.、和O 'Rand，M. G.（2000）J.Biol.Chem.275，30378-30386），并且在核接头中，不与DNA结合的组蛋白与NASP结合（Alekseev，O. M.，Bencieg D. C.的方法，理查森河T.，威德格伦E、和O 'Rand，M. G.（2003）J.Biol.Chem.278，8846-8852）。在小鼠生精细胞中，tNASP结合睾丸特异性连接体组蛋白H1 t。利用交联剂，3，3 '-二硫代双磺基琥珀酰亚胺丙酸酯，和质谱，我们已经确定了HSP 90作为睾丸/胚胎形式的NASP（tNASP）结合伴侣。体外实验表明，tNASP与HSP 90的结合可刺激HSP 90的ATP酶活性，并增加H1 t与tNASP的结合。HSP 90和tNASP存在于小鼠生精细胞的细胞核和细胞质组分中;然而，HSP 90仅在细胞质中与NASP结合。透化HeLa细胞的体外核输入试验表明，在没有任何其他细胞质因子的情况下，tNASP以能量和核定位信号依赖的方式将接头组蛋白转运到细胞核中。因此，我们推测，在细胞质中，接头组蛋白结合到含有NASP和HSP 90的复合物，其ATP酶活性通过结合NASP而被刺激。NASP-H1随后从复合物中释放并易位到细胞核，在细胞核中释放H1以与DNA结合。
NASP (nuclear autoantigenic sperm protein) is a linker histone-binding protein found in all dividing cells that is regulated by the cell cycle (Richardson, R. T., Batova, I. N., Widgren, E. E., Zheng, L. YL, Whitfield, M., Marzluff, W. F., and O'Rand, M. G. (2000) J. Biol. Chem. 275, 30378-30386), and in the nucleus linker histones not bound to DNA are bound to NASP (Alekseev, O. M., Bencieg D. C., Richardson R. T., Widgren E. E., and O'Rand, M. G. (2003) J. Biol. Chem. 278, 8846-8852). In mouse spermatogenic cells tNASP binds the testis-specific linker histone H1t. Utilizing a cross-linker, 3,3'-dithiobissulfosuceinimidyl propionate, and mass spectrometry, we have identified HSP90 as a testis/embryo form of NASP (tNASP)-binding partner. In vitro assays demonstrate that the association of tNASP with HSP90 stimulated the ATPase activity of HSP90 and increased the binding of H1t to tNASP. HSP90 and tNASP are present in both nuclear and cytoplasmic fractions of mouse spermatogenic cells; however, HSP90 bound to NASP only in the cytoplasm. In vitro nuclear import assays on permeabilized HeLa cells demonstrate that tNASP, in the absence of any other cytoplasmic factors, transports linker histones into the nucleus in an energy and nuclear localization signal-dependent manner. Consequently we hypothesize that in the cytoplasm linker histones are bound to a complex containing NASP and HSP90 whose ATPase activity is stimulated by binding NASP. NASP-H1 is subsequently released from the complex and translocates to the nucleus where the H1 is released for binding to the DNA.