Biopolym. Cell. 2005; 21(5):407-412.
http://dx.doi.org/10.7124/bc.000703
Structure and Function of Biopolymers
The beta subunit of casein kinase 2 as a novel binding partner of the ribosomal protein S6 kinase 1
1Panasyuk G. G., 1Nemzanyy I. O., 1Zhyvoloup A. M., 1Filonenko V. V., 1, 2Gout I. T.
  1. Institute of Molecular Biology and Genetics, NAS of Ukraine
    150, Akademika Zabolotnoho Str., Kyiv, Ukraine, 03680
  2. University College London
    Gower Str., London WC1E 6BT, UK

Abstract

Signaling pathways play a major role in regulation and coordination of many cellular processes. The kinases of 40S ribosomal subunit protein, S6K, S6K1 and S6K2, are an important player in signaling network. S6K belongs to and are regulated via PI3-kinase signaling pathway. It is known that S6K1 plays a key role in the regulation of mitogen activated protein biosynthesis facilitated by phosphorylation of ribosomal protein S6 that leads to the translation initiation of mRNA encoding components of the protein synthesis apparatus. Moreover, the participation of S6K1 in the regulation of cell cycle was found. Several protein kinases and phosphatases can use S6K as a substrate in vitro, but only for some of them the functional link to S6K has been demonstrated in vivo that is why molecular mechanisms of regulation of S6K activity in the cell remain unclear. Because of that it is very important to investigate protein targets of S6K in the cell, especially with the use of methodological approaches which would correspond to the conditions in vivo. The yeast-two hybrid system is a modern technique widely used in the world for the identification of protein-protein interactions in vivo. Using activated form of S6K1 as a bait, eight novel binding partners of S6K1 were identified. Among them the interaction between S6K1 and β regulatory subunit of casein kinase 2 has been discovered. Bioinformatic analysis of the primary structure of S6K1 and S6K2 has shown the presence of several potential CK2 phosphorylation sites, the Ser17 in S6K1 being the most preferential. Further studies have confirmed that S6K1 is phosphorylated at Ser17 by CK2 in the conditions of in vitro kinase reaction. The formation of S6K1/S6K2 βcomplex has been proven in vitro as well.
Keywords: S6K1, S6K2, Casein kinase 2 βsubunit, yeast two-hybrid system, phosphorylation
Full text: (PDF, in Ukrainian)

References

[1] Thomas G. The S6 kinase signaling pathway in the control of development and growth. Biol Res. 2002;35(2):305-13.
[2] Brennan P, Babbage JW, Thomas G, Cantrell D. p70(s6k) integrates phosphatidylinositol 3-kinase and rapamycin-regulated signals for E2F regulation in T lymphocytes. Mol Cell Biol. 1999;19(7):4729-38.
[3] Burnett PE, Blackshaw S, Lai MM, Qureshi IA, Burnett AF, Sabatini DM, Snyder SH. Neurabin is a synaptic protein linking p70 S6 kinase and the neuronal cytoskeleton. Proc Natl Acad Sci U S A. 1998;95(14):8351-6.
[4] Chou MM, Blenis J. The 70 kDa S6 kinase complexes with and is activated by the Rho family G proteins Cdc42 and Rac1. Cell. 1996;85(4):573-83.
[5] Peterson RT, Desai BN, Hardwick JS, Schreiber SL. Protein phosphatase 2A interacts with the 70-kDa S6 kinase and is activated by inhibition of FKBP12-rapamycinassociated protein. Proc Natl Acad Sci U S A. 1999;96(8):4438-42.
[6] Nemazanyy I, Panasyuk G, Zhyvoloup A, Panayotou G, Gout IT, Filonenko V. Specific interaction between S6K1 and CoA synthase: a potential link between the mTOR/S6K pathway, CoA biosynthesis and energy metabolism. FEBS Lett. 2004;578(3):357-62.
[7] Zhyvoloup A, Nemazanyy I, Babich A, Panasyuk G, Pobigailo N, Vudmaska M, Naidenov V, Kukharenko O, Palchevskii S, Savinska L, Ovcharenko G, Verdier F, Valovka T, Fenton T, Rebholz H, Wang ML, Shepherd P, Matsuka G, Filonenko V, Gout IT. Molecular cloning of CoA Synthase. The missing link in CoA biosynthesis. J Biol Chem. 2002;277(25):22107-10.
[8] Zhyvoloup OM, Nemazanyy IO, Pobigailo NV, Panasyuk GG, Palchevskyy SS, Kuharenko OP, Savinska LO, Ovcharenko GV, Vudmaska MI, Gout IT, Matsuka GKh, Filonenko VV. Use of yeast two-hybrid system in search of S6K1 and S6K2 binding partners. Biopolym Cell. 2002; 18(2):102-9.
[9] Panasyuk G, Nemazanyy I, Filonenko V, Zhyvoloup A. Large-scale yeast transformation in low-percentage agarose medium. Biotechniques. 2004;36(1):40-2, 44.
[10] Panasyuk G, Nemazanyy I, Ovcharenko G, Lyzogubov V, Gout I, Filonenko V. Generation and characterization of monoclonal antibodies to protein kinase 2 (CK2) beta subunit. Hybridoma (Larchmt). 2005;24(4):206-10.
[11] Savinska LO, Lyzogubov VV, Usenko VS, Ovcharenko GV, Gorbenko ON, Rodnin MV, Vudmaska MI, Pogribniy PV, Kyyamova RG, Panasyuk GG, Nemazanyy IO, Malets MS, Palchevskyy SS, Gout IT, Filonenko VV. Immunohistochemical analysis of S6K1 and S6K2 expression in human breast tumors. Eksp Onkol. 2004;26(1):24-30.
[12] Lawlor MA, Mora A, Ashby PR, Williams MR, Murray-Tait V, Malone L, Prescott AR, Lucocq JM, Alessi DR. Essential role of PDK1 in regulating cell size and development in mice. EMBO J. 2002;21(14):3728-38.
[13] Olsten ME, Litchfield DW. Order or chaos? An evaluation of the regulation of protein kinase CK2. Biochem Cell Biol. 2004;82(6):681-93.
[14] Litchfield DW. Protein kinase CK2: structure, regulation and role in cellular decisions of life and death. Biochem J. 2003;369(Pt 1):1-15.
[15] Meggio F, Pinna LA. One-thousand-and-one substrates of protein kinase CK2? FASEB J. 2003;17(3):349-68.
[16] Obenauer JC, Cantley LC, Yaffe MB. Scansite 2.0: Proteome-wide prediction of cell signaling interactions using short sequence motifs. Nucleic Acids Res. 2003;31(13):3635-41.