TY - JOUR
T1 - The DICE-binding Activity of KH Domain 3 of hnRNP K Is Affected by c-Src-mediated Tyrosine Phosphorylation
AU - Messias, Ana C.
AU - Harnisch, Christiane
AU - Ostareck-Lederer, Antje
AU - Sattler, Michael
AU - Ostareck, Dirk H.
N1 - Funding Information:
We thank H. Leffers and B.-J. Thiele for providing plasmids, and Nadine Flach for excellent technical assistance. CD measurements were performed by R. Golbik. The work was supported by grants from the Deutsche Forschungsgemeinschaft to D.H.O. (Os 135/2-1, 2-2, 2-3 and GRK1026) and to A.O.L. (Heisenberg Fellowship Os 290/1-1 and Os 290/2-1). A.C.M. acknowledges SFRH/BPD/14893/2004 and PRAXIS XXI/BPD/-22071/99 postdoctoral fellowships. M.S. and A.C.M. acknowledge support by the EU STREP FSG-V-RNA.
PY - 2006/8/18
Y1 - 2006/8/18
N2 - hnRNP K and hnRNP E1/E2 are RNA-binding proteins comprised of three hnRNP K-homology (KH) domains. These proteins are involved in the translational control and stabilization of mRNAs in erythroid cells. hnRNP E1 and hnRNP K regulate the translation of reticulocyte 15-lipoxygenase (r15-LOX) mRNA. Both proteins bind specifically to the differentiation control element (DICE) in the 3′ untranslated region (3′UTR) of the r15-LOX mRNA. It has been shown that hnRNP K is a substrate of the tyrosine kinase c-Src and that tyrosine phosphorylation by c-Src inhibits the binding of hnRNP K to the DICE. Here, we investigate which of the three KH domains of hnRNP E1 and hnRNP K mediate the DICE interaction. Using RNA-binding assays, we demonstrate DICE-binding of the KH domains 1 and 3 of hnRNP E1, and KH domain 3 of hnRNP K. Furthermore, with RNA-binding assays, NMR experiments and in vitro translation studies, we show that tyrosine 458 in KH domain 3 of hnRNP K is important for the DICE interaction and we provide evidence that it is a target of c-Src.
AB - hnRNP K and hnRNP E1/E2 are RNA-binding proteins comprised of three hnRNP K-homology (KH) domains. These proteins are involved in the translational control and stabilization of mRNAs in erythroid cells. hnRNP E1 and hnRNP K regulate the translation of reticulocyte 15-lipoxygenase (r15-LOX) mRNA. Both proteins bind specifically to the differentiation control element (DICE) in the 3′ untranslated region (3′UTR) of the r15-LOX mRNA. It has been shown that hnRNP K is a substrate of the tyrosine kinase c-Src and that tyrosine phosphorylation by c-Src inhibits the binding of hnRNP K to the DICE. Here, we investigate which of the three KH domains of hnRNP E1 and hnRNP K mediate the DICE interaction. Using RNA-binding assays, we demonstrate DICE-binding of the KH domains 1 and 3 of hnRNP E1, and KH domain 3 of hnRNP K. Furthermore, with RNA-binding assays, NMR experiments and in vitro translation studies, we show that tyrosine 458 in KH domain 3 of hnRNP K is important for the DICE interaction and we provide evidence that it is a target of c-Src.
KW - KH domain
KW - RNA binding
KW - hnRNP E1
KW - hnRNP K
KW - tyrosine phosphorylation
UR - http://www.scopus.com/inward/record.url?scp=33746353084&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2006.06.025
DO - 10.1016/j.jmb.2006.06.025
M3 - Article
C2 - 16854432
AN - SCOPUS:33746353084
SN - 0022-2836
VL - 361
SP - 470
EP - 481
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 3
ER -