Abstract
The ubiquitously expressed RNA-binding proteins Roquin-1 and Roquin-2 are essential for appropriate immune cell function and postnatal survival of mice. Roquin proteins repress target mRNAs by recognizing secondary structures in their 3'-UTRs and by inducing mRNA decay. However, it is unknown if other cellular proteins contribute to target control. To identify cofactors of Roquin, we used RNA interference to screen ~1500 genes involved in RNA-binding or mRNA degradation, and identified NUFIP2 as a cofactor of Roquin-induced mRNA decay. NUFIP2 binds directly and with high affinity to Roquin, which stabilizes NUFIP2 in cells. Post-transcriptional repression of human ICOS by endogenous Roquin proteins requires two neighboring non-canonical stem-loops in the ICOS 3'-UTR. This unconventional cis-element as well as another tandem loop known to confer Roquin-mediated regulation of the Ox40 3'-UTR, are bound cooperatively by Roquin and NUFIP2. NUFIP2 therefore emerges as a cofactor that contributes to mRNA target recognition by Roquin.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Amino Acid Sequence
-
Animals
-
Binding Sites
-
CD4-Positive T-Lymphocytes / cytology
-
CD4-Positive T-Lymphocytes / immunology*
-
Gene Expression Regulation
-
HEK293 Cells
-
HeLa Cells
-
Humans
-
Inducible T-Cell Co-Stimulator Protein / antagonists & inhibitors
-
Inducible T-Cell Co-Stimulator Protein / genetics*
-
Inducible T-Cell Co-Stimulator Protein / immunology
-
Inverted Repeat Sequences
-
Mice
-
Mice, Inbred C57BL
-
Nuclear Proteins / antagonists & inhibitors
-
Nuclear Proteins / genetics*
-
Nuclear Proteins / immunology
-
Nucleic Acid Conformation
-
Primary Cell Culture
-
Protein Binding
-
RNA Stability
-
RNA, Small Interfering / genetics
-
RNA, Small Interfering / metabolism
-
RNA-Binding Proteins / antagonists & inhibitors
-
RNA-Binding Proteins / genetics*
-
RNA-Binding Proteins / immunology
-
Receptors, OX40 / antagonists & inhibitors
-
Receptors, OX40 / genetics*
-
Receptors, OX40 / immunology
-
Recombinant Proteins / genetics
-
Recombinant Proteins / immunology
-
Repressor Proteins / genetics*
-
Repressor Proteins / immunology
-
Sequence Alignment
-
Sequence Homology, Amino Acid
-
Ubiquitin-Protein Ligases / genetics*
-
Ubiquitin-Protein Ligases / immunology
Substances
-
ICOS protein, human
-
Inducible T-Cell Co-Stimulator Protein
-
NUFIP2 protein, human
-
Nuclear Proteins
-
RC3H1 protein, human
-
RC3H2 protein, human
-
RNA, Small Interfering
-
RNA-Binding Proteins
-
Receptors, OX40
-
Recombinant Proteins
-
Repressor Proteins
-
TNFRSF4 protein, human
-
Ubiquitin-Protein Ligases