title: Netrin-1-induced local β-actin synthesis and growth cone guidance requires zipcode binding protein 1.
abstract: Local β-actin synthesis in growth cones of developing axons plays an important role in growth cone steering; however, the mRNA binding proteins required for this process are unknown. Here we used Zbp1/Imp1(-/)(-) mice to test the hypothesis that zipcode binding protein 1 (ZBP1) is required for the regulation of β-actin mRNA transport and local translation underlying growth cone guidance. To address the biological function of ZBP1, we developed a novel in vitro turning assay with primary cortical neuron balls having axons >1 mm in length and demonstrate that growth cones of mammalian neurons exhibit protein synthesis-dependent attraction to either netrin-1 or brain-derived neurotrophic factor (BDNF). Interestingly, this attraction is lost in Zbp1-deficient neurons. Furthermore, BDNF-stimulated β-actin mRNA localization was attenuated in Zbp1-deficient neurons, which impaired enrichment of β-actin protein in the growth cone. Finally, using a photoconvertible translation reporter, we found that ZBP1 is necessary for netrin-1 stimulated local translation of β-actin mRNA in axonal growth cones. Together, these results suggest that netrin-1- and BDNF-induced growth cone attraction required ZBP1-mediated local translation of β-actin mRNA, and therefore ZBP1 regulates protein synthesis-dependent axon guidance. Thus, mRNA binding proteins regulating local translation can control spatiotemporal protein expression in response to guidance cues and directional cell motility.
authors: Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors: Kristy
authors: K
authors: Welshhans
authors: Gary J
authors: GJ
authors: Bassell
mesh_terms: D000185:Actinin / Q000235:genetics / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D004622:Embryo, Mammalian; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D020439:Growth Cones / Q000187:drug effects*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation / Q000235:genetics; D009414:Nerve Growth Factors / Q000494:pharmacology*; D000075388:Netrin-1; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D010649:Phenylalanine / Q000235:genetics; D011247:Pregnancy; D011554:Pseudopodia / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D013997:Time Factors; D014162:Transfection / Q000379:methods; D025521:Tumor Suppressor Proteins / Q000494:pharmacology*; D014443:Tyrosine / Q000235:genetics
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D002352:Carrier Proteins; D009414:Nerve Growth Factors; C000617353:Ntn1 protein, mouse; C000617354:Ntn1 protein, rat; D012333:RNA, Messenger; C544534:Sp38 protein, mouse; D025521:Tumor Suppressor Proteins; C485184:enhanced green fluorescent protein; D000185:Actinin; D049452:Green Fluorescent Proteins; D000075388:Netrin-1; D014443:Tyrosine; D010649:Phenylalanine