title: RAP55: insights into an evolutionarily conserved protein family.
abstract: The RAP55 protein family is evolutionarily conserved in eukaryotes. Two highly conserved paralogues, RAP55A and RAP55B, exist in vertebrates; their functional properties and expression patterns remain to be compared. RAP55 proteins share multiple domains: the LSm14 domain, a serine/threonine rich region, an FDF (phenylalanine-aspartate-phenylalanine) motif, an FFD-TFG box and RGG (arginine-glycine-glycine) repeats. Together these domains are responsible for RAP55 proteins participating in translational repression, incorporation into mRNP particles, protein-protein interactions, P-body formation and stress granule localisation. All RAP55A proteins localise to P-body-like complexes either in the germline or in somatic cells. Xenopus laevis RAP55B has been shown to be part of translationally repressed mRNP complexes in early oocytes. Together these findings suggest that this protein family has evolved a common and fundamental role in the control of mRNA translation. Furthermore human RAP55A is an autoantigen detected in the serum of patients with primary biliary cirrhosis (PBC). The link between RAP55A, P-bodies and PBC remains to be elucidated.
authors: Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Road, Cambridge CB2 1GA, United Kingdom.
authors: Aline
authors: A
authors: Marnef
authors: John
authors: J
authors: Sommerville
authors: Michael R
authors: MR
authors: Ladomery
mesh_terms: D000818:Animals; D005057:Eukaryotic Cells / Q000502:physiology; D019143:Evolution, Molecular; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D012261:Ribonucleoproteins / Q000235:genetics / Q000502:physiology*; D029867:Xenopus Proteins / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis
chemical_list: C516955:RAP55 protein, Xenopus; D012333:RNA, Messenger; C510649:RNA-associated protein 55, human; D012097:Repressor Proteins; D012261:Ribonucleoproteins; D029867:Xenopus Proteins