Bonnet H, Filhol O, Truchet I, Brethenou P, Cochet C, Amalric F, Bouche G
Laboratoire de Biologie Moléculaire Eucaryote, CNRS, 118 route de Narbonne, 31062 Toulouse Cedex, France.
J Biol Chem. 1996 Oct 4;271(40):24781-7. doi: 10.1074/jbc.271.40.24781.
The presence of fibroblast growth factor-2 (FGF-2) in the nucleus has now been reported both in vitro and in vivo, but its nuclear functions are unknown. Here, we show that FGF-2 added to nuclear extract binds to protein kinase CK2 and nucleolin, a CK2 natural substrate. Added to baculovirus-infected cell extracts overexpressing CK2 or its isolated subunits, FGF-2 binds to the enzyme through its regulatory beta subunit. Using purified proteins, FGF-2 is shown to directly interact with CK2 and to stimulate CK2 activity toward nucleolin. Furthermore, a mitogenic-deficient FGF-2 mutant protein has an impaired ability to interact with CK2 and to stimulate CK2 activity using nucleolin as substrate. We propose that in growing cells, one function of nuclear FGF-2 is to modulate CK2 activity through binding to its regulatory beta subunit.
目前已有体外和体内研究报道成纤维细胞生长因子-2（FGF-2）存在于细胞核中，但其核功能尚不清楚。在此，我们发现添加到核提取物中的FGF-2可与蛋白激酶CK2及核仁素（一种CK2天然底物）结合。将FGF-2添加到过表达CK2或其分离亚基的杆状病毒感染细胞提取物中，FGF-2通过其调节性β亚基与该酶结合。使用纯化蛋白研究发现，FGF-2可直接与CK2相互作用，并刺激CK2对核仁素的活性。此外，有丝分裂缺陷型FGF-2突变蛋白与CK2相互作用以及以核仁素为底物刺激CK2活性的能力受损。我们提出，在生长中的细胞中，核FGF-2的一个功能是通过与CK2的调节性β亚基结合来调节CK2的活性。
