First published online March 7, 2005
Development 132, 705e (2005)
© The Company of Biologists Limited
Elongating insights into transcriptional regulation
In Drosophila, the patterns of homeotic gene transcription that
specify body segment identity are maintained by the polycomb group of
repressors and the trithorax group (trxG) of activators. On
p. 1623, Srinivasan
and colleagues report that the trxG protein Kismet maintains homeotic gene
transcription by facilitating an early step in transcriptional elongation by
RNA polymerase II (Pol II). kismet, which is needed for segmentation
and for body segment specification, encodes the isoforms KIS-L and KIS-S. The
researchers show that KIS-L associates with virtually all sites of
transcriptionally active chromatin on salivary gland polytene chromosomes
taken from Drosophila larvae. This distribution pattern largely
overlaps with that of Pol II. Furthermore, the levels of elongating Pol II and
of several elongation factors are reduced on polytene chromosomes from
kis mutant larvae. The researchers conclude that KIS-L, unexpectedly
given its specialised roles in development, plays a global role in
transcription by Pol II.
Related articles in Development:
- The Drosophila trithorax group protein Kismet facilitates an early step in transcriptional elongation by RNA Polymerase II
- Shrividhya Srinivasan, Jennifer A. Armstrong, Renate Deuring, Ina K. Dahlsveen, Helen McNeill, and John W. Tamkun
Development 2005 132: 1623-1635.
[Abstract]
[Full Text]
