转录因子Pax5在B细胞定向分化发育过程中发挥重要调控作用。B细胞定向分化发育相关的转录因子如PU.1、干扰素调节因子4(Interferon regulatory factor 4,IRF4)、IRF8和NF-κB结合在Pax5基因5’上游增强子区,转录因子EBF、STAT5结合在Pax5基因5’上游启动子区,从而共同促进Pax5基因的表达。表达的Pax5蛋白不仅通过IgH的V(D)J片段染色质的甲基化和乙酰化修饰来调节IgH V(D)J重排,并且通过B细胞特异性基因(mb-1、VpreB、λ5、CD19、BLNK等)表达调控B细胞的定向分化发育。若Pax5基因缺失,影响组蛋白H3-K9的修饰,导致B细胞向非B细胞分化。总之,Pax5在B细胞定向分化发育中起到重要调控作用。 The transcription factor Pax5 plays an important regulatory role in the development of B cell lineage. Transcription factors such as PU.1, Interferon regulatory factor 4 (IRF4), IRF8 and NF-κB, which are related to the development of B cell differentiation, are found in the 5 ’upstream enhancer region of Pax5 gene. The transcription factors EBF and STAT5 bind to The Pax5 gene 5 ’upstream promoter region, which together promote Pax5 gene expression. The expressed Pax5 protein regulates IgH V (D) J rearrangement not only by methylation and acetylation modification of the V (D) J fragment chromatin of IgH, but also by B cell-specific genes (mb-1, VpreB, , CD19, BLNK, etc.) regulate the development of directional differentiation of B cells. If the Pax5 gene is deleted, it affects the modification of histone H3-K9, resulting in the differentiation of B cells into non-B cells. In conclusion, Pax5 plays an important regulatory role in the development of B cell-directed differentiation.