TY - JOUR
T1 - Site-specific N-glycosylation of the S-locus receptor kinase and its role in the self-incompatibility response of the brassicaceae
AU - Yamamoto, Masaya
AU - Tantikanjana, Titima
AU - Nishio, Takeshi
AU - Nasrallah, Mikhail E.
AU - Nasrallah, June B.
N1 - Publisher Copyright:
© 2014 American Society of Plant Biologists. All rights reserved.
PY - 2014
Y1 - 2014
N2 - The S-locus receptor kinase SRK is a highly polymorphic transmembrane kinase of the stigma epidermis. Through allelespecific interaction with its pollen coat-localized ligand, the S-locus cysteine-rich protein SCR, SRK is responsible for recognition and inhibition of self pollen in the self-incompatibility response of the Brassicaceae. The SRK extracellular ligand binding domain contains several potential N-glycosylation sites that exhibit varying degrees of conservation among SRK variants. However, the glycosylation status and functional importance of these sites are currently unclear. We investigated this issue in transgenic Arabidopsis thaliana stigmas that express the Arabidopsis lyrata SRKb variant and exhibit an incompatible response toward SCRb-expressing pollen. Analysis of single- and multiple-glycosylation site mutations of SRKb demonstrated that, although five of six potential N-glycosylation sites in SRKb are glycosylated in stigmas, N-glycosylation is not important for SCRb-dependent activation of SRKb. Rather, N-glycosylation functions primarily to ensure the proper and efficient subcellular trafficking of SRK to the plasma membrane. The study provides insight into the function of a receptor that regulates a critical phase of the plant life cycle and represents a valuable addition to the limited information available on the contribution of N-glycosylation to the subcellular trafficking and function of plant receptor kinases.
AB - The S-locus receptor kinase SRK is a highly polymorphic transmembrane kinase of the stigma epidermis. Through allelespecific interaction with its pollen coat-localized ligand, the S-locus cysteine-rich protein SCR, SRK is responsible for recognition and inhibition of self pollen in the self-incompatibility response of the Brassicaceae. The SRK extracellular ligand binding domain contains several potential N-glycosylation sites that exhibit varying degrees of conservation among SRK variants. However, the glycosylation status and functional importance of these sites are currently unclear. We investigated this issue in transgenic Arabidopsis thaliana stigmas that express the Arabidopsis lyrata SRKb variant and exhibit an incompatible response toward SCRb-expressing pollen. Analysis of single- and multiple-glycosylation site mutations of SRKb demonstrated that, although five of six potential N-glycosylation sites in SRKb are glycosylated in stigmas, N-glycosylation is not important for SCRb-dependent activation of SRKb. Rather, N-glycosylation functions primarily to ensure the proper and efficient subcellular trafficking of SRK to the plasma membrane. The study provides insight into the function of a receptor that regulates a critical phase of the plant life cycle and represents a valuable addition to the limited information available on the contribution of N-glycosylation to the subcellular trafficking and function of plant receptor kinases.
UR - http://www.scopus.com/inward/record.url?scp=84961291963&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84961291963&partnerID=8YFLogxK
U2 - 10.1105/tpc.114.131987
DO - 10.1105/tpc.114.131987
M3 - Article
C2 - 25480368
AN - SCOPUS:84961291963
VL - 26
SP - 4749
EP - 4762
JO - Plant Cell
JF - Plant Cell
SN - 1040-4651
IS - 12
ER -