Tawfic S, Ahmed K
Cellular and Molecular Biochemistry Research Laboratory, Department of Veterans Affairs Medical Center, Minneapolis, Minnesota 55417.
J Biol Chem. 1994 Oct 7;269(40):24615-20.
Recently, we documented that a significant amount of nuclear casein kinase 2 (CK2) (a ubiquitous multipotential messenger-independent serine/threonine protein kinase) is associated with the nuclear matrix (NM), where it may be involved in the phosphorylation of several intrinsic proteins (Tawfic, S., and Ahmed, K. (1994) J. Biol. Chem. 269, 7489-7493). Both CK2 and NM have been implicated in cell growth and proliferation. To examine whether CK2 in the NM was regulated in relation to a growth stimulus, we employed androgen action in the prostate as a model of growth control. In rats, androgen deprivation leads to a differential loss of CK2 activity and protein from the NM fraction in the prostate. At 24 h after androgen deprivation, the NM-associated CK2 activity as well as immunoreactive protein decline by about 80%. By comparison, total nuclear CK2 activity decreased by only 37%. Androgen administration to the castrated rats evokes a rapid differential increase in CK2 activity in the NM, so that within 1 h following the androgenic stimulus, the CK2 activity increases by 110% in the NM fraction versus 45% in the total nuclei. We propose that the stimulus-mediated differential translocation of CK2 to NM may play a role in the transduction of growth signal.
最近，我们记录到大量的细胞核酪蛋白激酶2（CK2）（一种普遍存在的、不依赖信使的多潜能丝氨酸/苏氨酸蛋白激酶）与核基质（NM）相关联，它可能参与了几种内在蛋白的磷酸化过程（陶菲克，S.，和艾哈迈德，K.（1994）《生物化学杂志》269，7489 - 7493）。CK2和核基质都与细胞生长和增殖有关。为了研究核基质中的CK2是否与生长刺激相关而受到调节，我们以前列腺中的雄激素作用作为生长控制的模型。在大鼠中，雄激素剥夺导致前列腺核基质部分的CK2活性和蛋白出现差异性丧失。雄激素剥夺24小时后，与核基质相关的CK2活性以及免疫反应性蛋白下降约80%。相比之下，细胞核总CK2活性仅下降37%。给去势大鼠注射雄激素会迅速引起核基质中CK2活性的差异性快速增加，因此在雄激素刺激后1小时内，核基质部分的CK2活性增加了110%，而细胞核总体中的增加了45%。我们提出，刺激介导的CK2向核基质的差异性转位可能在生长信号转导中起作用。
