The Arabidopsis class I TCP transcription factor AtTCP11 is a developmental regulator with distinct DNA-binding properties due to the presence of a threonine residue at position 15 of the TCP domain

VIOLA, IL; UBERTI MANASSERO, NG; RIPOLLO, R; GONZÁLEZ, DH

BIOCHEMICAL JOURNAL

PORTLAND PRESS LTD

Lugar: Gran Bretaña; Año: 2011 p. 143 - 155

0264-6021

The TCP domain is a DNA-binding domain present in plant transcription factors that modulate different processes. In the present study, we show that Arabidopsis class I TCP proteins are able to interact with a dyad-symmetric sequence composed of twoGTGGGhalf-sites. TCP20 establishes symmetric interactions with the 5 half of each strand, whereas TCP11 interacts mainly with the 3 half. SELEX (systematic evolution of ligands by exponential enrichment) experiments with TCP15 and TCP20 indicated that these proteins have similar, although not identical, DNA-binding preferences and are able to interact with nonpalindromic binding sites of the type GTGGGNCCNN. TCP11 shows a different DNA-binding specificity, with a preference for the sequence GTGGGCCNNN. The distinct DNA-binding properties of TCP11 are due to the presence of a threonine residue at position 15 of the TCP domain, a position that is occupied by an arginine residue in most TCP proteins. TCP11 also forms heterodimers with TCP15 that have increased DNAbinding efficiency. The expression in plants of a repressor form of TCP11 demonstrated that this protein is a developmental regulator that influences the growth of leaves, stems and petioles, and pollen development. The results suggest that changes in DNA-binding preferences may be one of the mechanisms through which class I TCP proteins achieve functional specificity.