title: Subcellular TSC22D4 localization in cerebellum granule neurons of the mouse depends on development and differentiation.
abstract: We previously demonstrated that TSC22D4, a protein encoded by the TGF-β1-activated gene Tsc22d4 (Thg-1pit) and highly expressed in postnatal and adult mouse cerebellum with multiple post-translationally modified protein forms, moves to nucleus when in vitro differentiated cerebellum granule neurons (CGNs) are committed to apoptosis by hyperpolarizing KCl concentrations in the culture medium. We have now studied TSC22D4 cytoplasmic/nuclear localization in CGNs and Purkinje cells: (1) during CGN differentiation/maturation in vivo, (2) during CGN differentiation in vitro, and (3) by in vitro culturing ex vivo cerebellum slices under conditions favoring/inhibiting CGN/Purkinje cell differentiation. We show that TSC22D4 displays both nuclear and cytoplasmic localizations in undifferentiated, early postnatal cerebellum CGNs, irrespectively of CGN proliferation/migration from external to internal granule cell layer, and that it specifically accumulates in the somatodendritic and synaptic compartments when CGNs mature, as indicated by TSC22D4 abundance at the level of adult cerebellum glomeruli and apparent lack in CGN nuclei. These features were also observed in cerebellum slices cultured in vitro under conditions favoring/inhibiting CGN/Purkinje cell differentiation. In vitro TSC22D4 silencing with siRNAs blocked CGN differentiation and inhibited neurite elongation in N1E-115 neuroblastoma cells, pinpointing the relevance of this protein to CGN differentiation.
authors.affiliation: Department of Psychology, Section of Neuroscience, Istituto Pasteur-Fondazione Cenci Bolognetti and D. Bovet Research Center, Sapienza University of Rome, Rome, Italy.
authors.forename: Sonia
authors.initials: S
authors.lastname: Canterini
authors.forename: Adriana
authors.initials: A
authors.lastname: Bosco
authors.forename: Valentina
authors.initials: V
authors.lastname: Carletti
authors.forename: Andrea
authors.initials: A
authors.lastname: Fuso
authors.forename: Armando
authors.initials: A
authors.lastname: Curci
authors.forename: Franco
authors.initials: F
authors.lastname: Mangia
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Fiorenza
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D045744:Cell Line, Tumor; D002525:Cerebellar Cortex / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000378:metabolism*; D020868:Gene Silencing; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016501:Neurites / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009924:Organ Culture Techniques; D061251:Primary Cell Culture; D034741:RNA, Small Interfering / Q000494:pharmacology; D013347:Subcellular Fractions / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; C443111:Spacdr protein, mouse; D014157:Transcription Factors