NUFIP and the HSP90/R2TP chaperone bind the SMN complex and facilitate assembly of U4-specific proteins.
The Sm proteins are loaded on snRNAs by the SMN complex, but how snRNP-specific proteins are assembled remains poorly characterized. U4 snRNP and box C/D snoRNPs have structural similarities. They both contain the 15.5K and proteins with NOP domains (PRP31 for U4, NOP56/58 for snoRNPs). Biogenesis of box C/D snoRNPs involves NUFIP and the HSP90/R2TP chaperone system and here, we explore the function of this machinery in U4 RNP assembly. We show that yeast Prp31 interacts with several components of the NUFIP/R2TP machinery, and that these interactions are separable from each other. In human cells, PRP31 mutants that fail to stably associate with U4 snRNA still interact with components of the NUFIP/R2TP system, indicating that these interactions precede binding of PRP31 to U4 snRNA. Knock-down of NUFIP leads to mislocalization of PRP31 and decreased association with U4. Moreover, NUFIP is associated with the SMN complex through direct interactions with Gemin3 and Gemin6. Altogether, our data suggest a model in which the NUFIP/R2TP system is connected with the SMN complex and facilitates assembly of U4 snRNP-specific proteins.
Equipe labélisée Ligue contre le Cancer, Institut de Génétique Moléculaire de Montpellier, IGMM-UMR 5535 du CNRS-Université de Montpellier, 1919, route de Mende, 34293 Montpellier Cedex 5, France.
Jonathan
J
Bizarro
Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS-Université de Lorraine, Biopôle de l'Université de Lorraine, avenue de la forêt de Haye, BP 184, 54505 Vandoeuvre-les-Nancy Cedex, France.
Maxime
M
Dodré
Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS-Université de Lorraine, Biopôle de l'Université de Lorraine, avenue de la forêt de Haye, BP 184, 54505 Vandoeuvre-les-Nancy Cedex, France.
Alexandra
A
Huttin
Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS-Université de Lorraine, Biopôle de l'Université de Lorraine, avenue de la forêt de Haye, BP 184, 54505 Vandoeuvre-les-Nancy Cedex, France.
Bruno
B
Charpentier
Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS-Université de Lorraine, Biopôle de l'Université de Lorraine, avenue de la forêt de Haye, BP 184, 54505 Vandoeuvre-les-Nancy Cedex, France.
Florence
F
Schlotter
Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS-Université de Lorraine, Biopôle de l'Université de Lorraine, avenue de la forêt de Haye, BP 184, 54505 Vandoeuvre-les-Nancy Cedex, France.
Christiane
C
Branlant
Equipe labélisée Ligue contre le Cancer, Institut de Génétique Moléculaire de Montpellier, IGMM-UMR 5535 du CNRS-Université de Montpellier, 1919, route de Mende, 34293 Montpellier Cedex 5, France celine.verheggen@igmm.cnrs.fr.
Céline
C
Verheggen
Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS-Université de Lorraine, Biopôle de l'Université de Lorraine, avenue de la forêt de Haye, BP 184, 54505 Vandoeuvre-les-Nancy Cedex, France severine.massenet@univ-lorraine.fr.
Séverine
S
Massenet
Equipe labélisée Ligue contre le Cancer, Institut de Génétique Moléculaire de Montpellier, IGMM-UMR 5535 du CNRS-Université de Montpellier, 1919, route de Mende, 34293 Montpellier Cedex 5, France edouard.bertrand@igmm.cnrs.fr.
Edouard
E
Bertrand
D002460:Cell Line; D020541:Coiled Bodies / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005136:Eye Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D012342:RNA, Small Nuclear / Q000378:metabolism; D017414:Ribonucleoprotein, U4-U6 Small Nuclear / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D020718:Ribonucleoproteins, Small Nucleolar / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism*; D055532:SMN Complex Proteins / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017381:Spliceosomes / Q000235:genetics / Q000378:metabolism*
D005136:Eye Proteins; C000594604:Hit1 protein, S cerevisiae; D018832:Molecular Chaperones; C491451:PRP31 protein, S cerevisiae; C454222:PRPF31 protein, human; D012342:RNA, Small Nuclear; C402485:RSA1 protein, S cerevisiae; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; D020718:Ribonucleoproteins, Small Nucleolar; D012269:Ribosomal Proteins; D055532:SMN Complex Proteins; D029701:Saccharomyces cerevisiae Proteins; C402291:Snu13 protein, human; C405482:U4 small nuclear RNA