A nitrilase-like protein interacts with GCC box DNA-binding proteins involved in ethylene and defense responses.
Ethylene-responsive element-binding proteins (EREBPs) of tobacco (Nicotiana tabacum L.) bind to the GCC box of many pathogenesis-related (PR) gene promoters, including osmotin (PR-5). The two GCC boxes on the osmotin promoter are known to be required, but not sufficient, for maximal ethylene responsiveness. EREBPs participate in the signal transduction pathway leading from exogenous ethylene application and pathogen infection to PR gene induction. In this study EREBP3 was used as bait in a yeast two-hybrid interaction trap with a tobacco cDNA library as prey to isolate signal transduction pathway intermediates that interact with EREBPs. One of the strongest interactors was found to encode a nitrilase-like protein (NLP). Nitrilase is an enzyme involved in auxin biosynthesis. NLP interacted with other EREBP family members, namely tobacco EREBP2 and tomato (Lycopersicon esculentum L.) Pti4/5/6. The EREBP2-EREBP3 interaction with NLP required part of the DNA-binding domain. The specificity of interaction was further confirmed by protein-binding studies in solution. We propose that the EREBP-NLP interaction serves to regulate PR gene expression by sequestration of EREBPs in the cytoplasm.
Xu
P
P
Center for Plant Environmental Stress Physiology, 1165 Horticulture Building, Purdue University, West Lafayette, Indiana 47907-1165, USA.
Narasimhan
M L
ML
Samson
T
T
Coca
M A
MA
Huh
G H
GH
Zhou
J
J
Martin
G B
GB
Hasegawa
P M
PM
Bressan
R A
RA
D000595:Amino Acid Sequence; D000619:Aminohydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics; D010947:Plants, Toxic; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014026:Nicotiana / Q000166:cytology / Q000201:enzymology
D017931:DNA Primers; D004268:DNA-Binding Proteins; D005030:Ethylenes; D010940:Plant Proteins; C073139:osmotin protein, Nicotiana tabacum; C036216:ethylene; D000619:Aminohydrolases; C116432:nitrilase-like protein, Nicotiana tabacum; C021867:nitrilase