The intracellular localisation of TAF7L, a paralogue of transcription factor TFIID subunit TAF7, is developmentally regulated during male germ-cell differentiation.
Transcription regulation in male germ cells can involve specialised mechanisms and testis-specific paralogues of the general transcription machinery. Here we describe TAF7L, a germ-cell-specific paralogue of the TFIID subunit TAF7. TAF7L is expressed through most of the male germ-cell differentiation programme, but its intracellular localisation is dynamically regulated from cytoplasmic in spermatogonia and early spermatocytes to nuclear in late pachytene spermatocytes and haploid round spermatids. Import of TAF7L into the nucleus coincides with decreased TAF7 expression and a strong increase in nuclear TBP expression, which suggests that TAF7L replaces TAF7 as a TFIID subunit in late pachytene spermatocytes and in haploid cells. In agreement with this, biochemical experiments indicate that a subpopulation of TAF7L is tightly associated with TBP in both pachytene and haploid cells and TAF7L interacts with the TFIID subunit TAF1. We further show that TAF3, TAF4 and TAF10 are all strongly expressed in early spermatocytes, but that in contrast to TBP and TAF7L, they are downregulated in haploid cells. Hence, different subunits of the TFIID complex are regulated in distinct ways during male germ-cell differentiation. These results show for the first time how the composition of a general transcription factor such as TFIID and other TAF-containing complexes are modulated during a differentiation programme highlighting the unique nature of the transcription regulatory machinery in spermatogenesis.
Pointud
Jean-Christophe
JC
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 Rue Laurent Fries, 67404 Illkirch Cédex, France.
Mengus
Gabrielle
G
Brancorsini
Stefano
S
Monaco
Lucia
L
Parvinen
Martti
M
Sassone-Corsi
Paolo
P
Davidson
Irwin
I
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D005260:Female; D015870:Gene Expression; D007424:Intracellular Fluid / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D021122:Protein Subunits; D017386:Sequence Homology, Amino Acid; D013091:Spermatogenesis / Q000235:genetics; D013094:Spermatozoa / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000378:metabolism; D014018:Tissue Distribution; D035362:Transcription Factor TFIID / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D021122:Protein Subunits; C000598119:TAF7L protein, mouse; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID