TY  - JOUR
TI  - Evolution of the activation domain in a Hox transcription factor
AU  - Liu, Ying
AU  - Huang, Annie
AU  - Booth, RebeccaM.
AU  - Mendes, GabrielaGeraldo
AU  - Merchant, Zabeena
AU  - Matthews, KathleenS.
AU  - Bondos, SarahE.
T2  - The International Journal of Developmental Biology
AB  - Linking changes in amino acid sequences to the evolution of transcription regulatory domains is often complicated by the low sequence complexity and high mutation rates of intrinsically disordered protein regions. For the Hox transcription factor Ultrabithorax (Ubx), conserved motifs distributed throughout the protein sequence enable direct comparison of specific protein regions, despite variations in the length and composition of the intervening sequences. In cell culture, the strength of transcription activation by Drosophila melanogaster Ubx correlates with the presence of a predicted helix within its activation domain. Curiously, this helix is not preserved in species more divergent than flies, suggesting the nature of transcription activation may have evolved. To determine whether this helix contributes to Drosophila Ubx function in vivo, wild-type and mutant proteins were ectopically expressed in the developing wing and the phenotypes evaluated. Helix mutations alter Drosophila Ubx activity in the developing wing, demonstrating its functional importance in vivo. The locations of activation domains in Ubx orthologues were identified by testing the ability of truncation mutants to activate transcription in yeast one-hybrid assays. In Ubx orthologues representing 540 million years of evolution, the ability to activate transcription varies substantially. The sequence and the location of the activation domains also differ. Consequently, analogous regions of Ubx orthologues change function over time, and may activate transcription in one species, but have no activity, or even inhibit transcription activation in another species. Unlike homeodomain-DNA binding, the nature of transcription activation by Ubx has substantially evolved.
PY  - 2018
DO  - 10.1387/ijdb.180151sb
VL  - 62
IS  - 11-12
SP  - 745
EP  - 753
J2  - Int. J. Dev. Biol.
LA  - en
SN  - 0214-6282
SN  - 1696-3547
UR  - https://ijdb.ehu.eus/article/180151sb
Y2  - 2024/11/23/10:27:16
ER  -