Hurwitz M E, Blobel G
Laboratory of Cell Biology, Rockefeller University, Howard Hughes Medical Institute, New York 10021, USA.
J Cell Biol. 1995 Sep;130(6):1275-81. doi: 10.1083/jcb.130.6.1275.
We have isolated and characterized the gene encoding a novel essential nucleoporin of 82 kD, termed NUP82. Indirect immunofluorescence of cells containing an epitope tagged copy of the NUP82 localized it to the nuclear pore complex (NPC). Primary structure analysis indicates that the COOH-terminal 195 amino acids contain a putative coiled-coil domain. Deletion of the COOH-terminal 87 amino acids of this domain causes slower cell growth; deletion of the COOH-terminal 108 amino acids results in slower growth at 30 degrees C and lethality at 37 degrees C. Cells in which the last 108 amino acids of NUP82 have been deleted, when shifted to 37 degrees C, do not display any gross morphological defects in their nuclear pore complexes or nuclear envelopes. They do, however, accumulate poly(A)+ RNA in their nuclei at 37 degrees C. We propose that NUP82 acts as a linker to tether nucleoporins directly involved in nuclear transport to pore scaffolding via its coiled-coil domain.
我们已经分离并鉴定了编码一种名为NUP82的新型82kD必需核孔蛋白的基因。对含有NUP82抗原表位标签拷贝的细胞进行间接免疫荧光分析,将其定位于核孔复合体(NPC)。一级结构分析表明,COOH末端的195个氨基酸包含一个假定的卷曲螺旋结构域。缺失该结构域COOH末端的87个氨基酸会导致细胞生长缓慢;缺失COOH末端的108个氨基酸会导致在30℃时生长缓慢,在37℃时致死。缺失NUP82最后108个氨基酸的细胞,当转移到37℃时,其核孔复合体或核膜没有显示出任何明显的形态缺陷。然而,它们在37℃时确实会在细胞核中积累多聚腺苷酸(poly(A)+)RNA。我们提出,NUP82作为一种连接物,通过其卷曲螺旋结构域将直接参与核运输的核孔蛋白与孔支架连接起来。