Ectopic expression of the tetratricopeptide repeat domain of SPINDLY causes defects in gibberellin response

Citation
Ts. Tseng et al., Ectopic expression of the tetratricopeptide repeat domain of SPINDLY causes defects in gibberellin response, PLANT PHYSL, 126(3), 2001, pp. 1250-1258
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT PHYSIOLOGY
ISSN journal
0032-0889 → ACNP
Volume
126
Issue
3
Year of publication
2001
Pages
1250 - 1258
Database
ISI
SICI code
0032-0889(200107)126:3<1250:EEOTTR>2.0.ZU;2-Q
Abstract
The SPINDLY (SPY) protein of Arabidopsis is a negative regulator of gibbere llin (GA) response. The SPY protein has 10 copies of the tetratricopeptide repeat (TPR) at the N terminus. TPR motifs function as protein-protein inte raction domains. Several spy alleles are affected only in the TPR region su ggesting that protein-protein interactions mediated by this domain are impo rtant for proper GA signaling. We have used a reverse genetics approach to further investigate the role of the TFR domain. The TPR domain of SPY was o verexpressed in wild-type, gai, and spy plants. Expression of the TPR domai n alone is not sufficient to rescue spy mutants. Expression of the TPR doma in in a wild-type background produces phenotypes similar to those caused by loss-of-function spy mutants including resistance to GA biosynthesis inhib itors, short hypocotyl length, and early flowering. The dwarfing of the flo ral shoot internodes caused by the gai mutation was suppressed by expressio n of the TRP domain. Expression of the TPR domain had no effect on the abun dance of endogenous SPY mRNA. : The TPR domain was found to interact with S PY both in vitro and in yeast two-hybrid assays. These data indicate that t he TPR domain of SPY can participate in protein-protein interactions and th at these interactions are important for the proper functioning of SPY.