Fragile , Xenopus/Amphibian, mental retardation syndrome-related protein 1 (F, Xenopus/Amphibian,R1) is an RNA-binding protein required for embryonic and postnatal development of muscle tissue. F, Xenopus/Amphibian,R1 regulates intracellular transport and local translation of certain mRNAs. F, Xenopus/Amphibian,R1 shuttles between the nucleus and cytoplasm and associates with polyribosomes,Porcineredominantly with the 60S ribosomal subunit. Three transcript variants encoding different isoforms have been found for F, Xenopus/Amphibian,R1.