Journal of Cell Science 116, e902 (2003)
Copyright © 2003 The Company of Biologists Limited
Sperm-specific transcriptional machinery
The general transcription factor TFIID plays a critical role in
transcription by RNA polymerase II, nucleating assembly of preinitiation
complexes at the transcription start site. TFIID contains the TATA-binding
protein (TBP) and a variety of TBP-associated factors (TAFs). The majority of
these are ubiquitously expressed, but recent work has hinted that some might
occasionally be replaced by tissue-specific variants. Irwin Davidson and
co-workers have therefore examined the expression pattern and dynamics of the
testes-specific TAF7 variant TAF7L (see
p. 1847). They show that TAF7L
is present throughout spermatogenesis but that it is initially present solely
in the cytoplasm and enters the nucleus only once spermatocytes have reached
late pachytene. They also show that TAF7L is tightly associated with TBP at
this stage and observe that its arrival in the nucleus correlates with a
decline in TAF7 expression, as well as upregulation of TBP. Additional
experiments reveal that expression of other TAFs is also dynamically
regulated, leading the authors to propose that spermatocytes assemble a unique
form of the general transcriptional machinery, which could have specialized
functions in haploid cells.
Related articles in JCS:
- The intracellular localisation of TAF7L, a paralogue of transcription factor TFIID subunit TAF7, is developmentally regulated during male germ-cell differentiation
- Jean-Christophe Pointud, Gabrielle Mengus, Stefano Brancorsini, Lucia Monaco, Martti Parvinen, Paolo Sassone-Corsi, and Irwin Davidson
JCS 2003 116: 1847-1858.
[Abstract]
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