CERKL, a retinal disease gene, encodes an mRNA-binding protein that localizes in compact and untranslated mRNPs associated with microtubules.
The function of CERKL (CERamide Kinase Like), a causative gene of retinitis pigmentosa and cone-rod dystrophy, still awaits characterization. To approach its cellular role we have investigated the subcellular localization and interaction partners of the full length CERKL isoform, CERKLa of 532 amino acids, in different cell lines, including a photoreceptor-derived cell line. We demonstrate that CERKLa is a main component of compact and untranslated mRNPs and that associates with other RNP complexes such as stress granules, P-bodies and polysomes. CERKLa is a protein that binds through its N-terminus to mRNAs and interacts with other mRNA-binding proteins like eIF3B, PABP, HSP70 and RPS3. Except for eIF3B, these interactions depend on the integrity of mRNAs but not of ribosomes. Interestingly, the C125W CERKLa pathological mutant does not interact with eIF3B and is absent from these complexes. Compact mRNPs containing CERKLa also associate with microtubules and are found in neurites of neural differentiated cells. These localizations had not been reported previously for any member of the retinal disorders gene family and should be considered when investigating the pathogenic mechanisms and therapeutical approaches in these diseases.
Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe, Valencia, Spain.
Alihamze
A
Fathinajafabadi
Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe, Valencia, Spain.
Eva
E
Pérez-Jiménez
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain ; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
Marina
M
Riera
Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe, Valencia, Spain ; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
Erwin
E
Knecht
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain ; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain.
Roser
R
Gonzàlez-Duarte
D017398:Alternative Splicing; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D002853:Chromatography, Liquid; D024202:Electrophoretic Mobility Shift Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D017404:In Situ Hybridization, Fluorescence; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism* / Q000473:pathology; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D011132:Polyribosomes / Q000378:metabolism; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D012261:Ribonucleoproteins / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D012261:Ribonucleoproteins; C026452:messenger ribonucleoprotein; D017853:Phosphotransferases (Alcohol Group Acceptor); C066324:ceramide kinase