| Type: | Family | Name: | Cytoplasmic FMR1-interacting |
| Description: | Cytoplasmic fragile X mental retardation protein (FMRP) interacting protein belongs to a highly conserved but, as yet, functionally uncharacterisedfamily. Absence of FMRP is responsible for pathologic manifestations in Fragile X Syndrome, the most frequent cause of inherited mental retardation[]. FMRP is an RNA-binding protein that may have a role in local proteintranslation at neuronal dendrites and in dendritic spine maturation [].CYFIP1 and CYFIP2, which share a high level of sequence identity, have recently been identified as cytoplasmic FMRP interacting proteins [].CYFIP2 interacts with FMRP-related proteins FXR1P/2P, while CYFIP1 interacts exclusively with FMRP. The FMRP-CYFIP interaction involves the domain ofFMRP that also mediates homo- and heteromerisation, suggesting competition between the various interaction partners. CYFIP1 also interacts with the small GTPase Rac1 implicated in development and maintenance of neuronal structures. CYFIP1/2 are both present in synaptosomal extracts []. PIR121 (121F-specific p53 inducible RNA) is another functionally uncharacterised member of this family. The PIR121 gene maps to humanchromosome 5q34, a region frequently translocated in acute myeloid leukaemia but not known to be amplified or deleted in solid tumours. Interactionbetween PIR121 and FMRP has been demonstrated, and hence PIR121 has also been termed CYFIP2 (Cytoplasmic FMRP Interacting Protein 2) [, ].Shyc (Selective HYbridizing Clone) is a cytoplasmic protein of unknown function, expressed in the developing and embryonic nervous system. Theprotein has also been designated CYFIP1 due to the high sequence identity (98.7%) to its human orthologue. The CYFIP orthologues in Caenorhabditis elegansand Drosophila melanogaster(Fruit fly) share about 51% and 67% sequence identity with the human proteins, respectively []. The high level ofconservation manifest throughout the entire CYFIP sequence between various orthologues suggests a number of functionally/structurally important domains. | Short Name: | Cytoplasmic_FMR1-int |
