Alternative splicing of the histone demethylase LSD1/KDM1 contributes to the modulation of neurite morphogenesis in the mammalian nervous system.
A variety of chromatin remodeling complexes are thought to orchestrate transcriptional programs that lead neuronal precursors from earliest commitment to terminal differentiation. Here we show that mammalian neurons have a specialized chromatin remodeling enzyme arising from a neurospecific splice variant of LSD1/KDM1, histone lysine specific demethylase 1, whose demethylase activity on Lys4 of histone H3 has been related to gene repression. We found that alternative splicing of LSD1 transcript generates four full-length isoforms from combinatorial retention of two identified exons: the 4 aa exon E8a is internal to the amine oxidase domain, and its inclusion is restricted to the nervous system. Remarkably, the expression of LSD1 splice variants is dynamically regulated throughout cortical development, particularly during perinatal stages, with a progressive increase of LSD1 neurospecific isoforms over the ubiquitous ones. Notably, the same LSD1 splice dynamics can be fairly recapitulated in cultured cortical neurons. Functionally, LSD1 isoforms display in vitro a comparable demethylase activity, yet the inclusion of the sole exon E8a reduces LSD1 repressor activity on a reporter gene. Additional distinction among isoforms is supported by the knockdown of neurospecific variants in cortical neurons resulting in the inhibition of neurite maturation, whereas overexpression of the same variants enhances it. Instead, perturbation of LSD1 isoforms that are devoid of the neurospecific exon elicits no morphogenic effect. Collectively, results demonstrate that the arousal of neuronal LSD1 isoforms pacemakes early neurite morphogenesis, conferring a neurospecific function to LSD1 epigenetic activity.
Zibetti
Cristina
C
Department of Biology and Genetics for Medical Sciences, University of Milan, 20122 Milan, Italy.
Adamo
Antonio
A
Binda
Claudia
C
Forneris
Federico
F
Toffolo
Emanuela
E
Verpelli
Chiara
C
Ginelli
Enrico
E
Mattevi
Andrea
A
Sala
Carlo
C
Battaglioli
Elena
E
D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001921:Brain / Q000166:cytology; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D005091:Exons / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D016678:Genome; D049452:Green Fluorescent Proteins / Q000235:genetics; D051528:Guanylate Kinases / Q000378:metabolism; D006367:HeLa Cells; D056466:Histone Demethylases / Q000235:genetics*; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods; D008958:Models, Molecular; D009024:Morphogenesis / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016501:Neurites / Q000502:physiology*; D009474:Neurons / Q000166:cytology*; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017470:Receptors, Glutamate / Q000378:metabolism; D000074407:SAP90-PSD95 Associated Proteins; D014162:Transfection / Q000379:methods
D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017470:Receptors, Glutamate; D000074407:SAP90-PSD95 Associated Proteins; D049452:Green Fluorescent Proteins; D056466:Histone Demethylases; D052248:Nitric Oxide Synthase Type I; C495195:KDM1A protein, human; C106868:CASK kinases; D051528:Guanylate Kinases