Ubiquitin lysine 63 chain forming ligases regulate apical dominance in Arabidopsis.
Lys-63-linked multiubiquitin chains play important roles in signal transduction in yeast and in mammals, but the functions for this type of chain in plants remain to be defined. The RING domain protein RGLG2 (for RING domain Ligase2) from Arabidopsis thaliana can be N-terminally myristoylated and localizes to the plasma membrane. It can form Lys-63-linked multiubiquitin chains in an in vitro reaction. RGLG2 has overlapping functions with its closest sequelog, RGLG1, and single mutants in either gene are inconspicuous. rglg1 rglg2 double mutant plants exhibit loss of apical dominance and altered phyllotaxy, two traits critically influenced by the plant hormone auxin. Auxin and cytokinin levels are changed, and the plants show a decreased response to exogenously added auxin. Changes in the abundance of PIN family auxin transport proteins and synthetic lethality with a mutation in the auxin transport regulator BIG suggest that the directional flow of auxin is modulated by RGLG activity. Modification of proteins by Lys-63-linked multiubiquitin chains is thus important for hormone-regulated, basic plant architecture.
Yin
Xiao-Jun
XJ
Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
Volk
Sara
S
Ljung
Karin
K
Mehlmer
Norbert
N
Dolezal
Karel
K
Ditengou
Franck
F
Hanano
Shigeru
S
Davis
Seth J
SJ
Schmelzer
Elmon
E
Sandberg
Göran
G
Teige
Markus
M
Palme
Klaus
K
Pickart
Cecile
C
Bachmair
Andreas
A
D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D001692:Biological Transport / Q000187:drug effects; D002384:Catalysis / Q000187:drug effects; D003583:Cytokinins / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism; D008239:Lysine / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D018519:Meristem / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D019814:Myristic Acid / Q000494:pharmacology; D010641:Phenotype; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development*; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
D003583:Cytokinins; D007210:Indoleacetic Acids; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D019814:Myristic Acid; D044767:Ubiquitin-Protein Ligases; D008239:Lysine