Sepp-Lorenzino L, Azrolan N, Coleman P S
Dept of Biology, New York University, NY 10003.
FEBS Lett. 1989 Mar 13;245(1-2):110-6. doi: 10.1016/0014-5793(89)80202-9.
A set of isoprenylated proteins has been detected in rapidly proliferating, suspension-grown murine lymphoma cells. Our evidence indicates that all of these isoprenylated proteins are phosphorylated. Subsequent to a 24 h incubation with mevinolin to deplete the intracellular mevalonate (MVA) level, cells were incubated with [3H]MVA and/or 32Pi and both total cell and subcellular fraction proteins were resolved via 1- and 2-D gel electrophoresis, then assessed via subsequent autoradiography. The phospho-isoprenylated proteins comprise a set spanning a molecular mass range of 21-69 kDa and all dispay acidic pI. MVA-derivatized proteins of 21-24 kDa, which consist of multiple isoforms, are present in both cytosolic and nuclear fractions. Larger phospho-isoprenylated protein species (44-69 kDa) are specifically localized within the nucleus, where applicable extraction protocols indicate that they are part of or closely affiliated with the nuclear matrix-intermediate filament (NM-IF) components. The localization of the 69 kDa prenylated species within the NM-IF fraction, together with evidence of its phosphorylation, supports recent indications that this protein is the nuclear matrix component lamin B.
在快速增殖的悬浮培养小鼠淋巴瘤细胞中检测到一组异戊二烯化蛋白。我们的证据表明，所有这些异戊二烯化蛋白都被磷酸化。在用美伐他汀孵育24小时以耗尽细胞内甲羟戊酸（MVA）水平后，将细胞与[3H]MVA和/或32Pi一起孵育，然后通过一维和二维凝胶电泳分离总细胞和亚细胞组分蛋白，随后通过放射自显影进行评估。磷酸化异戊二烯化蛋白包括一组分子量范围为21-69 kDa的蛋白，且所有蛋白均显示酸性pI。由多种异构体组成的21-24 kDa的MVA衍生化蛋白存在于胞质和核组分中。较大的磷酸化异戊二烯化蛋白种类（44-69 kDa）特异性定位于细胞核内，适用的提取方案表明它们是核基质-中间丝（NM-IF）组分的一部分或与之密切相关。69 kDa异戊二烯化蛋白在NM-IF组分中的定位及其磷酸化证据支持了最近的迹象，即该蛋白是核基质组分核纤层蛋白B。
