Structural modules for receptor dimerization in the S-locus receptor kinase extracellular domain.
نویسندگان
چکیده
The highly polymorphic S-locus receptor kinase (SRK) is the stigma determinant of specificity in the self-incompatibility response of the Brassicaceae. SRK spans the plasma membrane of stigma epidermal cells, and it is activated in an allele-specific manner on binding of its extracellular region (eSRK) to its cognate pollen coat-localized S-locus cysteine-rich (SCR) ligand. SRK, like several other receptor kinases, forms dimers in the absence of ligand. To identify domains in SRK that mediate ligand-independent dimerization, we assayed eSRK for self-interaction in yeast. We show that SRK dimerization is mediated by two regions in eSRK, primarily by a C-terminal region inferred by homology modeling/fold recognition techniques to assume a PAN_APPLE-like structure, and secondarily by a region containing a signature sequence of the S-domain gene family, which might assume an EGF-like structure. We also show that eSRK exhibits a marked preference for homodimerization over heterodimerization with other eSRK variants and that this preference is mediated by a small, highly variable region within the PAN_APPLE domain. Thus, the extensive polymorphism exhibited by the eSRK not only determines differential affinity toward the SCR ligand, as has been assumed thus far, but also underlies a previously unrecognized allelic specificity in SRK dimerization. We propose that preference for SRK homodimerization explains the codominance exhibited by a majority of SRKs in the typically heterozygous stigmas of self-incompatible plants, whereas an increased propensity for heterodimerization combined with reduced affinity of heterodimers for cognate SCRs might underlie the dominant-recessive or mutual weakening relationships exhibited by some SRK allelic pairs.
منابع مشابه
G-protein Coupled Receptor Dimerization
A growing body of evidence suggests that GPCRs exist and function as dimers or higher oligomers. The evidence for GPCR dimerization comes from biochemical, biophysical and functional studies. In addition, researchers have shown the occurrence of heterodimerization between different members of the GPCR family. Two receptors can interact with each other to make a dimer through their extracellular...
متن کاملIn silico prediction of B cell epitopes of the extracellular domain of insulin-like growth factor-1 receptor
The insulin-like growth factor-1 receptor (IGF-1R) is a transmembrane receptor with tyrosine kinase activity. The receptor plays a critical role in cancer. Using monoclonal antibodies (MAbs) against the IGF-1R, typically blocks ligand binding and enhances down-regulation of the cell-surface IGF-1R. Some MAbs such as cixutumumab are under clinical trial investigation. Targeting multiple distinct...
متن کاملEffect of apelin on cardiac contractility in acute reno-vascular hypertension: The role of apelin receptor and kappa opioid receptor heterodimerization
Objective(s): Apelin/APJ system plays an important role in the regulation of myocardial contractility (MC) and blood pressure. Opioid receptors (OPRs) are also important cardiovascular regulators and exert many of their effects through modulating the function of other systems. This study analyzed the interaction between APJ and kappa OPRs (KOR) in cardiac responsiveness to apelin in acute reno-...
متن کاملRecombinant Expression of the Non-glycosylated Extracellular Domain of Human Transforming Growth Factorβ Type II Receptor Using the Baculovirus Expression System in Sf21 Insect Cells
Transforming growth factor beta (TGFβ1, β2, and β3) are 25 kDa disulfide-linked homodimers that regulate many aspects of cellular functions, consist of proliferation, differentiation, adhesion and extracellular matrix formation. TGFβs mediate their biological activities by binding of growth factor ligand to two related, functionally distinct, single-pass transmembrane receptor kinases, known as...
متن کاملP-105: Genetic Variation of Kinase Insert Domain-Containing Receptor Gene and Its Association with Recurrent Spontaneous Abortion
Background Recurrent spontaneous abortion has been defined two or more consecutive miscarriages at 20 weeks pregnancy and one of diseases that can lead to physical, psychological and economical for the individual problems. Recently number of polymorphisms in several genes was examined for association analyses in pregnant women which related to endanger the life of the fetus. In present study we...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 104 29 شماره
صفحات -
تاریخ انتشار 2007