HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Goitsuka, R. Articles by Chen2, C.-l. H. Search for Related Content PubMed PubMed Citation Articles by Goitsuka, R. Articles by Chen2, C.-l. H.

Genomic Structure and Transcriptional Regulation of the Early B Cell Gene chB1¹

Ryo Goitsuka^*,, Hiroshi Mamada^*, Daisuke Kitamura^*, Max D. Cooper^,,¶,||,# and Chen-lo H. Chen2^,||

^* Division of Molecular Biology, Institute for Biological Sciences, Science University of Tokyo, Tokyo, Japan; Inheritance and Variation Group, Precursory Research of Embryonic Science and Technology, Japan Science and Technology Corporation, Noda, Japan; and Division of Developmental and Clinical Immunology, Departments of Medicine, ^¶ Pediatrics, and ^|| Microbiology, University of Alabama, and ^# Howard Hughes Medical Institute, Birmingham AL 35294

The avian B cell differentiation Ag chB1 is a membrane glycoprotein relative of the mammalian B cell differentiation Ag CD72. Unlike CD72, this C-type lectin is expressed in relatively high levels on immature B cells in the bursa of Fabricius and is down-regulated on mature B cells in the periphery. An immunoreceptor tyrosine-based inhibitory motif in the chB1 cytoplasmic tail suggests a potential regulatory role in intrabursal B cell development. To gain further insight into the selective expression and function of chB1, we determined the genomic organization of chB1 and examined the mechanism of its transcriptional regulation. The 8-exon chB1 gene proved to have very similar organization to that of mouse CD72, further supporting the idea that chB1 is a CD72 relative. As for mouse CD72, the chB1 promoter region lacks a TATA box but contains a conserved initiator element. The 131-bp region (-161 to -30) proximal to the transcriptional start site, which contains a potential early B cell factor binding site, is essential for the B lineage stage-specific transcription of chB1, whereas PU.1 and B cell-specific activator protein/Pax5 have been shown to play important roles in CD72 promoter activity and cell-type specificity. This analysis suggests that differences in transcriptional regulation of these phylogenetically related genes may determine the differences in expression pattern and, therefore, the function of avian chB1 and mammalian CD72 during B cell development.

This article has been cited by other articles:

				N. Fujiwara, S. Hidano, H. Mamada, K. Ogasawara, D. Kitamura, M. D Cooper, N. Hozumi, C.-l. H Chen, and R. Goitsuka A novel avian homologue of CD72, chB1r, down modulates BCR-mediated activation signals Int. Immunol., May 1, 2006; 18(5): 775 - 783. [Abstract] [Full Text] [PDF]