TY - JOUR
T1 - Brassinosteroid-Insensitive-1 Is a Ubiquitously Expressed Leucine-Rich Repeat Receptor Serine/Threonine Kinase
AU - Friedrichsen, Danielle M.
AU - Joazeiro, Claudio A. P.
AU - Li, Jianming
AU - Hunter, Tony
AU - Chory, Joanne
N1 - This work was supported by grants from the U.S. Department of Agriculture (to J.C.) and the National Institutes of Health (to T.H.). J.C. is an associate investigator of the Howard Hughes Medical Institute. T.H. is a Frank and Else Schilling American Cancer Society research professor. D.M.F. was partially supported by a National Institutes of Health Training Grant. C.A.P.J. and J.L. were American Cancer Society Postdoctoral Fellows.
PY - 2000/8
Y1 - 2000/8
N2 - Brassinosteroid (BR) mutants of Arabidopsis have pleiotropic phenotypes and provide evidence that BRs function through-out the life of the plant from seedling development to senescence. Screens for BR signaling mutants identified one locus, BRI1, which encodes a protein with homology to leucine-rich repeat receptor serine (Ser)/threonine (Thr) kinases. Twenty-seven alleles of this putative BR receptor have been isolated to date, and we present here the identification of the molecular lesions of 14 recessive alleles that represent five new mutations. BR-insensitive-1 (BRI1) is expressed at high levels in the meristem, root, shoot, and hypocotyl of seedlings and at lower levels later in development. Confocal microscopy analysis of full-length BRI1 fused to green fluorescent protein indicates that BRI1 is localized in the plasma membrane, and an in vitro kinase assay indicates that BRI1 is a functional Ser/Thr kinase. Among the bri1 mutants identified are mutants in the kinase domain, and we demonstrate that one of these mutations severely impairs BRI1 kinase activity. Therefore, we conclude that BRI1 is a ubiquitously expressed leucine-rich repeat receptor that plays a role in BR signaling through Ser/Thr phosphorylation.
AB - Brassinosteroid (BR) mutants of Arabidopsis have pleiotropic phenotypes and provide evidence that BRs function through-out the life of the plant from seedling development to senescence. Screens for BR signaling mutants identified one locus, BRI1, which encodes a protein with homology to leucine-rich repeat receptor serine (Ser)/threonine (Thr) kinases. Twenty-seven alleles of this putative BR receptor have been isolated to date, and we present here the identification of the molecular lesions of 14 recessive alleles that represent five new mutations. BR-insensitive-1 (BRI1) is expressed at high levels in the meristem, root, shoot, and hypocotyl of seedlings and at lower levels later in development. Confocal microscopy analysis of full-length BRI1 fused to green fluorescent protein indicates that BRI1 is localized in the plasma membrane, and an in vitro kinase assay indicates that BRI1 is a functional Ser/Thr kinase. Among the bri1 mutants identified are mutants in the kinase domain, and we demonstrate that one of these mutations severely impairs BRI1 kinase activity. Therefore, we conclude that BRI1 is a ubiquitously expressed leucine-rich repeat receptor that plays a role in BR signaling through Ser/Thr phosphorylation.
UR - http://www.scopus.com/inward/record.url?scp=0033836946&partnerID=8YFLogxK
U2 - 10.1104/pp.123.4.1247
DO - 10.1104/pp.123.4.1247
M3 - Journal article
C2 - 10938344
AN - SCOPUS:0033836946
SN - 0032-0889
VL - 123
SP - 1247
EP - 1255
JO - Plant Physiology
JF - Plant Physiology
IS - 4
ER -
