title: YY1 plays an essential role at all stages of B-cell differentiation.
abstract: Ying Yang 1 (YY1) is a ubiquitously expressed transcription factor shown to be essential for pro-B-cell development. However, the role of YY1 in other B-cell populations has never been investigated. Recent bioinformatics analysis data have implicated YY1 in the germinal center (GC) B-cell transcriptional program. In accord with this prediction, we demonstrated that deletion of YY1 by Cγ1-Cre completely prevented differentiation of GC B cells and plasma cells. To determine if YY1 was also required for the differentiation of other B-cell populations, we deleted YY1 with CD19-Cre and found that all peripheral B-cell subsets, including B1 B cells, require YY1 for their differentiation. Transitional 1 (T1) B cells were the most dependent upon YY1, being sensitive to even a half-dosage of YY1 and also to short-term YY1 deletion by tamoxifen-induced Cre. We show that YY1 exerts its effects, in part, by promoting B-cell survival and proliferation. ChIP-sequencing shows that YY1 predominantly binds to promoters, and pathway analysis of the genes that bind YY1 show enrichment in ribosomal functions, mitochondrial functions such as bioenergetics, and functions related to transcription such as mRNA splicing. By RNA-sequencing analysis of differentially expressed genes, we demonstrated that YY1 normally activates genes involved in mitochondrial bioenergetics, whereas it normally down-regulates genes involved in transcription, mRNA splicing, NF-κB signaling pathways, the AP-1 transcription factor network, chromatin remodeling, cytokine signaling pathways, cell adhesion, and cell proliferation. Our results show the crucial role that YY1 plays in regulating broad general processes throughout all stages of B-cell differentiation.
authors.affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037;
authors.forename: Eden
authors.initials: E
authors.lastname: Kleiman
authors.affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037;
authors.forename: Haiqun
authors.initials: H
authors.lastname: Jia
authors.affiliation: Department of Molecular Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Loguercio
authors.affiliation: Department of Molecular Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037.
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Su
authors.affiliation: Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037; feeney@scripps.edu.
authors.forename: Ann J
authors.initials: AJ
authors.lastname: Feeney
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D002454:Cell Differentiation; D019070:Cell Lineage; D004265:DNA Helicases / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D018858:Germinal Center / Q000166:cytology / Q000502:physiology*; D056484:Jumonji Domain-Containing Histone Demethylases / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D050986:YY1 Transcription Factor / Q000502:physiology*
chemical_list: D050986:YY1 Transcription Factor; C494699:Yy1 protein, mouse; D056484:Jumonji Domain-Containing Histone Demethylases; C523761:Kdm6b protein, mouse; C509277:Mi-2beta protein, mouse; D004265:DNA Helicases
keywords: B lymphocytes; YY1; differentiation; mitochondrial bioenergetics; transcription