hnRNP A1 and hnRNP H can collaborate to modulate 5' splice site selection.
The mammalian proteins hnRNP A1 and hnRNP H control many splicing decisions in viral and cellular primary transcripts. To explain some of these activities, we have proposed that self-interactions between bound proteins create an RNA loop that represses internal splice sites while simultaneously activating the external sites that are brought in closer proximity. Here we show that a variety of hnRNP H binding sites can affect 5' splice site selection. The addition of two sets of hnRNP H sites in a model pre-mRNA modulates 5' splice site selection cooperatively, consistent with the looping model. Notably, binding sites for hnRNP A1 and H on the same pre-mRNA can similarly collaborate to modulate 5' splice site selection. The C-terminal portion of hnRNP H that contains the glycine-rich domains (GRD) is essential for splicing activity, and it can be functionally replaced by the GRD of hnRNP A1. Finally, we used the bioluminescence resonance energy transfer (BRET) technology to document the existence of homotypic and heterotypic interactions between hnRNP H and hnRNP A1 in live cells. Overall, our study suggests that interactions between different hnRNP proteins bound to distinct locations on a pre-mRNA can change its conformation to affect splicing decisions.
Fisette
Jean-François
JF
Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec H3C 3J7, Canada.
Toutant
Johanne
J
Dugré-Brisson
Samuel
S
Desgroseillers
Luc
L
Chabot
Benoit
B
D001483:Base Sequence / Q000502:physiology; D001665:Binding Sites / Q000235:genetics; D002478:Cells, Cultured; D006367:HeLa Cells; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D009690:Nucleic Acid Conformation; D011485:Protein Binding / Q000502:physiology; D022821:RNA Splice Sites / Q000235:genetics / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity / Q000235:genetics; D014162:Transfection
D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D022821:RNA Splice Sites