82-FIP, a novel FMRP (fragile X mental retardation protein) interacting protein, shows a cell cycle-dependent intracellular localization.
FMRP is an RNA binding protein whose absence produces pathological manifestations of the fragile-X syndrome. FMRP is a component of mRNP complexes found in association with actively translating polyribosomes, RNA complexes trafficking in neurites, RNA granules in cytoplasm and, in Drosophila, with the RNAi machinery. We report here the identification and characterization of a novel FMRP-interacting protein associated to polyribosomes as a component of mRNP complexes containing FMRP. We named this protein 82-FIP (82-kD FMRP Interacting Protein). FMRP interacts with 82-FIP through a novel interaction motif located in its N-terminal region. The distribution of 82-FIP in different areas of the brain is very similar to that of FMRP. However, unlike FMRP, 82-FIP is found in both nucleus and cytoplasm in some neurons, while it appears only cytoplasmic in others. Subcellular distribution of 82-FIP is cell cycle-dependent in cultured cells, suggesting that the composition of some FMRP-containing RNP complexes may be cell cycle-modulated.
Bardoni
Barbara
B
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP 10142, 1 rue Laurent Fries, 67404 Illkirch Cedex, France. bardoni@igbmc.u-strasbg.fr
Castets
Marie
M
Huot
Marc-Etienne
ME
Schenck
Annette
A
Adinolfi
Salvatore
S
Corbin
François
F
Pastore
Annalisa
A
Khandjian
Edouard W
EW
Mandel
Jean-Louis
JL
D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D051860:Fragile X Messenger Ribonucleoprotein 1; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D011132:Polyribosomes / Q000502:physiology*; D011485:Protein Binding; D016601:RNA-Binding Proteins
D002352:Carrier Proteins; D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C497683:FMR1 protein, human; C477652:NUFIP2 protein, human