Redundant role of tissue-selective TAF(II)105 in B lymphocytes.
Regulated gene expression is a complex process achieved through the function of multiple protein factors acting in concert at a given promoter. The transcription factor TFIID is a central component of the machinery regulating mRNA synthesis by RNA polymerase II. This large multiprotein complex is composed of the TATA box binding protein (TBP) and several TBP-associated factors (TAF(II)s). The recent discovery of multiple TBP-related factors and tissue-specific TAF(II)s suggests the existence of specialized TFIID complexes that likely play a critical role in regulating transcription in a gene- and tissue-specific manner. The tissue-selective factor TAF(II)105 was originally identified as a component of TFIID derived from a human B-cell line. In this report we demonstrate the specific induction of TAF(II)105 in cultured B cells in response to bacterial lipopolysaccharide (LPS). To examine the in vivo role of TAF(II)105, we have generated TAF(II)105-null mice by homologous recombination. Here we show that B-lymphocyte development is largely unaffected by the absence of TAF(II)105. TAF(II)105-null B cells can proliferate in response to LPS, produce relatively normal levels of resting antibodies, and can mount an immune response by producing antigen-specific antibodies in response to immunization. Taken together, we conclude that the function of TAF(II)105 in B cells is likely redundant with the function of other TAF(II)105-related cellular proteins.
Department of Molecular and Cell Biology, University of California at Berkeley, 94720-3204, USA.
Richard N
RN
Freiman
Shane R
SR
Albright
Leslie E
LE
Chu
Shuang
S
Zheng
Hong-Erh
HE
Liang
William C
WC
Sha
Robert
R
Tjian
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D015153:Blotting, Western; D002455:Cell Division; D002469:Cell Separation; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000378:metabolism; D005434:Flow Cytometry; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D051379:Mice; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000378:metabolism; D013154:Spleen / Q000378:metabolism / Q000473:pathology; D035381:TATA-Binding Protein Associated Factors; D013997:Time Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D035381:TATA-Binding Protein Associated Factors; C491103:Taf4b protein, mouse; D035362:Transcription Factor TFIID; D014157:Transcription Factors