RT Journal Article
SR Electronic
T1 Arabidopsis AtCUL3a and AtCUL3b Form Complexes with Members of the BTB/POZ-MATH Protein Family
JF Plant Physiology
JO Plant Physiol.
FD American Society of Plant Biologists
SP 83
OP 93
DO 10.1104/pp.104.052654
VO 137
IS 1
A1 Weber, Henriette
A1 Bernhardt, Anne
A1 Dieterle, Monika
A1 Hano, Perdita
A1 Mutlu, Aysegül
A1 Estelle, Mark
A1 Genschik, Pascal
A1 Hellmann, Hanjo
YR 2005
UL http://www.plantphysiol.org/content/137/1/83.abstract
AB The ubiquitin proteasome pathway in plants has been shown to be important for many developmental processes. The E3 ubiquitin-protein ligases facilitate transfer of the ubiquitin moiety to substrate proteins. Many E3 ligases contain cullin proteins as core subunits. Here, we show that Arabidopsis (Arabidopsis thaliana) AtCUL3 proteins interact in yeast two-hybrid and in vitro pull-down assays with proteins containing a BTB/POZ (broad complex, tramtrack, bric-a-brac/pox virus and zinc finger) motif. By changing specific amino acid residues within the proteins, critical parts of the cullin and BTB/POZ proteins are defined that are required for these kinds of interactions. In addition, we show that AtCUL3 proteins assemble with the RING-finger protein AtRBX1 and are targets for the RUB-conjugation pathway. The analysis of AtCUL3a and AtCUL3b expression as well as several BTB/POZ-MATH genes indicates that these genes are expressed in all parts of the plant. The results presented here provide strong evidence that AtCUL3a and AtCUL3b can assemble in Arabidopsis with BTB/POZ-MATH and AtRBX1 proteins to form functional E3 ligases.