title: A critical role of the Thy28-MYH9 axis in B cell-specific expression of the Pax5 gene in chicken B cells.
abstract: Accumulating evidence suggests that Pax5 plays essential roles in B cell lineage commitment. However, molecular mechanisms of B cell-specific expression of Pax5 are not fully understood. Here, we applied insertional chromatin immunoprecipitation (iChIP) combined with stable isotope labeling using amino acids in cell culture (SILAC) (iChIP-SILAC) to direct identification of proteins interacting with the promoter region of the endogenous single-copy chicken Pax5 gene. By comparing B cells with macrophage-like cells trans-differentiated by ectopic expression of C/EBPβ, iChIP-SILAC detected B cell-specific interaction of a nuclear protein, Thy28/Thyn1, with the Pax5 1A promoter. Trans-differentiation of B cells into macrophage-like cells caused down-regulation of Thy28 expression. Loss-of-function of Thy28 induced decrease in Pax5 expression and recruitment of myosin-9 (MYH9), one of Thy28-interacting proteins, to the Pax5 1A promoter. Loss-of-function of MYH9 also induced decrease in Pax5 expression. Thus, our analysis revealed that Thy28 is functionally required for B cell-specific expression of Pax5 via recruitment of MYH9 to the Pax5 locus in chicken B cells.
authors.affiliation: Chromatin Biochemistry Research Group, Combined Program on Microbiology and Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
authors.forename: Toshitsugu
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Chromatin Biochemistry Research Group, Combined Program on Microbiology and Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
authors.forename: Fusako
authors.initials: F
authors.lastname: Kitaura
authors.affiliation: Chromatin Biochemistry Research Group, Combined Program on Microbiology and Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
authors.forename: Hodaka
authors.initials: H
authors.lastname: Fujii
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism*; D018929:Cell Culture Techniques; D002460:Cell Line; D002645:Chickens / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D005786:Gene Expression Regulation; D008264:Macrophages / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D051757:PAX5 Transcription Factor / Q000235:genetics* / Q000378:metabolism
chemical_list: D030161:Avian Proteins; D009687:Nuclear Proteins; D051757:PAX5 Transcription Factor; C438108:Thy28 protein, Gallus gallus; D018995:Myosin Heavy Chains