The exon junction complex component Magoh controls brain size by regulating neural stem cell division.
Brain structure and size require precise division of neural stem cells (NSCs), which self-renew and generate intermediate neural progenitors (INPs) and neurons. The factors that regulate NSCs remain poorly understood, and mechanistic explanations of how aberrant NSC division causes the reduced brain size seen in microcephaly are lacking. Here we show that Magoh, a component of the exon junction complex (EJC) that binds RNA, controls mouse cerebral cortical size by regulating NSC division. Magoh haploinsufficiency causes microcephaly because of INP depletion and neuronal apoptosis. Defective mitosis underlies these phenotypes, as depletion of EJC components disrupts mitotic spindle orientation and integrity, chromosome number and genomic stability. In utero rescue experiments showed that a key function of Magoh is to control levels of the microcephaly-associated protein Lis1 during neurogenesis. Our results uncover requirements for the EJC in brain development, NSC maintenance and mitosis, thereby implicating this complex in the pathogenesis of microcephaly.
Silver
Debra L
DL
Genetic Disease Research Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, Maryland, USA.
Watkins-Chow
Dawn E
DE
Schreck
Karisa C
KC
Pierfelice
Tarran J
TJ
Larson
Denise M
DM
Burnetti
Anthony J
AJ
Liaw
Hung-Jiun
HJ
Myung
Kyungjae
K
Walsh
Christopher A
CA
Gaiano
Nicholas
N
Pavan
William J
WJ
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000235:genetics / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000235:genetics; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000473:pathology*; D001973:Bromodeoxyuridine / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D002455:Cell Division / Q000235:genetics*; D004252:DNA Mutational Analysis; D004622:Embryo, Mammalian; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008831:Microcephaly / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics; D009474:Neurons / Q000473:pathology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D009929:Organ Size / Q000235:genetics; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000502:physiology*; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection
C491198:Eomes protein, mouse; D005136:Eye Proteins; D018398:Homeodomain Proteins; C491493:Magoh protein, mouse; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012333:RNA, Messenger; D012097:Repressor Proteins; D020825:T-Box Domain Proteins; D049452:Green Fluorescent Proteins; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; C513190:Pafah1b1 protein, mouse; D001973:Bromodeoxyuridine