TY - JOUR
T1 - Protein-protein interaction among hnRNPs shuttling between nucleus and cytoplasm
AU - Kim, Jong Heon
AU - Hahm, Bumsuk
AU - Kim, Yoon Ki
AU - Choi, Mieyoung
AU - Jang, Sung Key
N1 - Funding Information:
We thank Drs G. Dreyfuss and M. S. Swanson for providing us plasmids pBSO1, pALTER1-K(wt), pHC12, and pHCL3 encoding hnRNPs. The present study was supported, in part, by grants from the G7 Program and the Molecular Medicine Research Group Program of MOST, and by HMP-98-B-3-0020.
PY - 2000/5/5
Y1 - 2000/5/5
N2 - Heterogeneous nuclear ribonucleoproteins (hnRNPs) are involved in several RNA-related biological processes such as transcription, pre-mRNA processing, mature mRNA transport to the cytoplasm, and translation. About 20 major hnRNPs from A1 to U are known. Among them, hnRNP A, D, E, I, and K are known to shuttle between the nucleus and the cytoplasm. hnRNP E2 has been seen to stabilize α-globin mRNA and to enhance polioviral mRNA translation. hnRNP K modulates transcription and translation of some mRNAs, hnRNP I and its homologue hnRNP L have been suggested to enhance translation of some IRES-dependent mRNAs. In order to better understand the molecular mechanisms of the biological functions of hnRNPs, we investigated protein-protein interactions of six hnRNPs (hnRNP A1, C1, E2, I, K, and L) using the yeast two-hybrid system and in vitro co-precipitation assays. All of the hnRNPs tested exerted homomeric interactions, and hnRNP E2, I, K, and L interacted with each other. In the case of hnRNP E2 and hnRNP K, the N-terminal half of the proteins containing two KH (K homologous) domains were required for protein-protein interaction, and the second quarter of hnRNP I and hnRNP L containing RRM2 (RNA recognition motif 2) was essential for protein-protein interaction, hnRNP A1 and C1 did not form complexes with other hnRNPs in our assay systems. This suggests that the hnRNPs could fall into two groups: one group, including hnRNP A1 and C1, involved in hnRNP core complex formation and another group, including hnRNP E2, I, K, and L, involved in a variety of RNA-related biological processes. Different combinations of the proteins of the second group may facilitate different biological processes in conjunction with other factors. (C) 2000 Academic Press.
AB - Heterogeneous nuclear ribonucleoproteins (hnRNPs) are involved in several RNA-related biological processes such as transcription, pre-mRNA processing, mature mRNA transport to the cytoplasm, and translation. About 20 major hnRNPs from A1 to U are known. Among them, hnRNP A, D, E, I, and K are known to shuttle between the nucleus and the cytoplasm. hnRNP E2 has been seen to stabilize α-globin mRNA and to enhance polioviral mRNA translation. hnRNP K modulates transcription and translation of some mRNAs, hnRNP I and its homologue hnRNP L have been suggested to enhance translation of some IRES-dependent mRNAs. In order to better understand the molecular mechanisms of the biological functions of hnRNPs, we investigated protein-protein interactions of six hnRNPs (hnRNP A1, C1, E2, I, K, and L) using the yeast two-hybrid system and in vitro co-precipitation assays. All of the hnRNPs tested exerted homomeric interactions, and hnRNP E2, I, K, and L interacted with each other. In the case of hnRNP E2 and hnRNP K, the N-terminal half of the proteins containing two KH (K homologous) domains were required for protein-protein interaction, and the second quarter of hnRNP I and hnRNP L containing RRM2 (RNA recognition motif 2) was essential for protein-protein interaction, hnRNP A1 and C1 did not form complexes with other hnRNPs in our assay systems. This suggests that the hnRNPs could fall into two groups: one group, including hnRNP A1 and C1, involved in hnRNP core complex formation and another group, including hnRNP E2, I, K, and L, involved in a variety of RNA-related biological processes. Different combinations of the proteins of the second group may facilitate different biological processes in conjunction with other factors. (C) 2000 Academic Press.
KW - In vitro co-precipitation
KW - Protein-protein interaction
KW - RNA-related processes
KW - Shuttling hnRNPs
KW - Yeast two-hybrid
UR - http://www.scopus.com/inward/record.url?scp=0034607554&partnerID=8YFLogxK
U2 - 10.1006/jmbi.2000.3687
DO - 10.1006/jmbi.2000.3687
M3 - Article
C2 - 10772858
AN - SCOPUS:0034607554
SN - 0022-2836
VL - 298
SP - 395
EP - 405
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 3
ER -