Dynamic Association of the Fragile X Mental Retardation Protein as a Messenger Ribonucleoprotein between Microtubules and Polyribosomes

• DOI: 10.1091/mbc.e07-06-0583
• Publication Date: 2007-10-31T21:06:56Z
• Authors: Houping Wang; Jason B. Dictenberg; Li Ku; Wen Li; Gary J. Bassell; Yue Feng
• Keywords: Polysome; Messenger RNP; Translational regulation

The fragile X mental retardation protein (FMRP) is a selective RNA-binding that regulates translation and plays essential roles in synaptic function. FMRP bound to specific mRNA ligands, actively transported into neuronal processes microtubule-dependent manner, associated with polyribosomes engaged elongation. However, the biochemical relationship between FMRP-microtubule association FMRP-polyribosome remains elusive. Here, we report although majority of incorporated elongating soluble cytoplasm, microtubule-associated predominantly retained translationally dormant, polyribosome-free messenger ribonucleoprotein (mRNP) complexes. Interestingly, increased when mRNPs are dynamically released from as result inhibiting initiation. Furthermore, I304N mutant fails be microtubules mRNP particles dendrites microtubule-dependent, 3,5-dihydroxyphenylglycine-stimulated manner similar kinetics wild-type FMRP. Hence, FMRP-mRNP complexes travel on wait for activity-dependent translational derepression at site dual participation dormant suggests distinct dendritic transport regulation, two phases control local production accommodate plasticity.