The function of many of the pre-mRNA-binding proteins in mRNA biogenesis is unclear. We have analyzed the biochemical function of the hnRNP K protein by using a mouse cDNA clone. A previous study indicated that the expression of hnRNP K activates c-myc promoter in transient transfection assays. We show that the expression of hnRNP K results in a trans-activation of a variety of RNA polymerase II promoters. The trans-activation function depends on the sequences of hnRNP K that are also necessary for RNA binding. However, the RNA binding motifs are not sufficient for trans-activation. We could identify a mutant that bound RNA in vitro but was impaired in its ability to trans-activate the reporter genes. The trans-activation was not a result of the stabilization of the reporter mRNA, because hnRNP K increased the steady-state level of the reporter mRNA without altering its decay rate. By doing nuclear run-on assays, we provide evidence that the hnRNP K protein trans-activates the reporter genes by increasing the level of transcription.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				N. K. Mukhopadhyay, J. Kim, B. Cinar, A. Ramachandran, M. H. Hager, D. Di Vizio, R. M. Adam, M. A. Rubin, P. Raychaudhuri, A. De Benedetti, et al. Heterogeneous Nuclear Ribonucleoprotein K Is a Novel Regulator of Androgen Receptor Translation Cancer Res., March 15, 2009; 69(6): 2210 - 2218. [Abstract] [Full Text] [PDF]

				M. Notari, P. Neviani, R. Santhanam, B. W. Blaser, J.-S. Chang, A. Galietta, A. E. Willis, D. C. Roy, M. A. Caligiuri, G. Marcucci, et al. A MAPK/HNRPK pathway controls BCR/ABL oncogenic potential by regulating MYC mRNA translation Blood, March 15, 2006; 107(6): 2507 - 2516. [Abstract] [Full Text] [PDF]

				D. Alex and K. A. W. Lee RGG-boxes of the EWS oncoprotein repress a range of transcriptional activation domains Nucleic Acids Res., March 2, 2005; 33(4): 1323 - 1331. [Abstract] [Full Text] [PDF]

				J. Ostrowski, Y. Kawata, D. S. Schullery, O. N. Denisenko, and K. Bomsztyk Transient recruitment of the hnRNP K protein to inducibly transcribed gene loci Nucleic Acids Res., July 15, 2003; 31(14): 3954 - 3962. [Abstract] [Full Text] [PDF]

				L. Lacroix, H. Lienard, E. Labourier, M. Djavaheri-Mergny, J. Lacoste, H. Leffers, J. Tazi, C. Helene, and J.-L. Mergny Identification of two human nuclear proteins that recognise the cytosine-rich strand of human telomeres in vitro Nucleic Acids Res., April 1, 2000; 28(7): 1564 - 1575. [Abstract] [Full Text] [PDF]

				B. Charroux, C. Angelats, L. Fasano, S. Kerridge, and C. Vola The Levels of the bancal Product, a Drosophila Homologue of Vertebrate hnRNP K Protein, Affect Cell Proliferation and Apoptosis in Imaginal Disc Cells Mol. Cell. Biol., November 1, 1999; 19(11): 7846 - 7856. [Abstract] [Full Text] [PDF]

				D. S. Schullery, J. Ostrowski, O. N. Denisenko, L. Stempka, M. Shnyreva, H. Suzuki, M. Gschwendt, and K. Bomsztyk Regulated Interaction of Protein Kinase Cdelta with the Heterogeneous Nuclear Ribonucleoprotein K Protein J. Biol. Chem., May 21, 1999; 274(21): 15101 - 15109. [Abstract] [Full Text] [PDF]

				Q. Du, I. N. Melnikova, and P. D. Gardner Differential Effects of Heterogeneous Nuclear Ribonucleoprotein K on Sp1- and Sp3-mediated Transcriptional Activation of a Neuronal Nicotinic Acetylcholine Receptor Promoter J. Biol. Chem., July 31, 1998; 273(31): 19877 - 19883. [Abstract] [Full Text] [PDF]

				U. Delling, M. Raymond, and E. Schurr Identification of Saccharomyces cerevisiae Genes Conferring Resistance to Quinoline Ring-Containing Antimalarial Drugs Antimicrob. Agents Chemother., May 1, 1998; 42(5): 1034 - 1041. [Abstract] [Full Text]

				S. Hayes, P. Shiyanov, X. Chen, and P. Raychaudhuri DDB, a Putative DNA Repair Protein, Can Function as a Transcriptional Partner of E2F1 Mol. Cell. Biol., January 1, 1998; 18(1): 240 - 249. [Abstract] [Full Text]

				O. N. Denisenko, B. O'Neill, J. Ostrowski, I. Van Seuningen, and K. Bomsztyk Zik1, a Transcriptional Repressor That Interacts with the Heterogeneous Nuclear Ribonucleoprotein Particle K Protein J. Biol. Chem., November 1, 1996; 271(44): 27701 - 27706. [Abstract] [Full Text] [PDF]

				K. K. C. Li and K. A. W. Lee Transcriptional Activation by the Ewing's Sarcoma (EWS) Oncogene Can Be Cis-repressed by the EWS RNA-binding Domain J. Biol. Chem., July 21, 2000; 275(30): 23053 - 23058. [Abstract] [Full Text] [PDF]

				M. Mandal, R. Vadlamudi, D. Nguyen, R.-A. Wang, L. Costa, R. Bagheri-Yarmand, J. Mendelsohn, and R. Kumar Growth Factors Regulate Heterogeneous Nuclear Ribonucleoprotein K Expression and Function J. Biol. Chem., March 23, 2001; 276(13): 9699 - 9704. [Abstract] [Full Text] [PDF]

				H. Habelhah, K. Shah, L. Huang, A. L. Burlingame, K. M. Shokat, and Z.'e. Ronai Identification of New JNK Substrate Using ATP Pocket Mutant JNK and a Corresponding ATP Analogue J. Biol. Chem., May 18, 2001; 276(21): 18090 - 18095. [Abstract] [Full Text] [PDF]

				G. Fabini, R. Raijmakers, S. Hayer, M. A. Fouraux, G. J. M. Pruijn, and G. Steiner The Heterogeneous Nuclear Ribonucleoproteins I and K Interact with a Subset of the Ro Ribonucleoprotein-associated Y RNAs in Vitro and in Vivo J. Biol. Chem., June 1, 2001; 276(23): 20711 - 20718. [Abstract] [Full Text] [PDF]

				O. V. Bajenova, R. Zimmer, E. Stolper, J. Salisbury-Rowswell, A. Nanji, and P. Thomas Heterogeneous RNA-binding Protein M4 Is a Receptor for Carcinoembryonic Antigen in Kupffer Cells J. Biol. Chem., August 10, 2001; 276(33): 31067 - 31073. [Abstract] [Full Text] [PDF]