Biomaterial Database

N-terminal half of the cGMP phosphodiesterase gamma-subunit contributes to stabilization of the GTPase-accelerating protein complex. 2011

Lian-Wang Guo, and Arnold E Ruoho

Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA. lianwangguo@wisc.edu

In the visual signal terminating transition state, the cyclic GMP phosphodiesterase (PDE6) inhibitory γ-subunit (PDEγ) stimulates GTPase activity of the α-subunit of transducin (αt) by enhancing the interaction between αt and its regulator of G protein signaling (RGS9), which is constitutively bound to the type 5 G protein β-subunit (β5). Although it is known from a crystal structure of partial molecules that the PDEγ C terminus contacts with both αt and RGS9, contributions from the intrinsically disordered PDEγ N-terminal half remain unclear. In this study, we were able to investigate this issue using a photolabel transfer strategy that allows for mapping the interface of full-length proteins. We observed label transfer from PDEγ N-terminal positions 50, 30, and 16 to RGS9·β5 in the GTPase-accelerating protein (GAP) complex composed of PDEγ·αt·RGS9·β5. In support of a direct PDEγ N-terminal interaction with RGS9·β5, the PDEγ N-terminal peptide PDEγ(1-61) abolished label transfer to RGS9·β5, and another N-terminal peptide, PDEγ(10-30), disassembled the GAP complex in label transfer and pulldown experiments. Furthermore, we determined that the PDEγ C-terminal interaction with αt was enhanced whereas the N-terminal interaction was weakened upon changing the αt conformation from the signaling state to the transition state. This "rearrangement" of PDEγ domain interactions with αt appears to facilitate the interaction of the PDEγ N-terminal half with RGS9·β5 and hence its contribution to optimal stabilization of the GAP complex.

UI	MeSH Term	Description	Entries
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D054707	Cyclic Nucleotide Phosphodiesterases, Type 6	A cyclic nucleotide phosphodiesterase subfamily that is highly specific for CYCLIC GMP. It is found predominantly in the outer segment PHOTORECEPTOR CELLS of the RETINA. It is comprised of two catalytic subunits, referred to as alpha and beta, that form a dimer. In addition two regulatory subunits, referred to as gamma and delta, modulate the activity and localization of the enzyme.	Cyclic Nucleotide Phosphodiesterases, Type 6, alpha Subunit,Cyclic Nucleotide Phosphodiesterases, Type 6, beta Subunit,Cyclic Nucleotide Phosphodiesterases, Type 6, delta Subunit,Cyclic Nucleotide Phosphodiesterases, Type 6, gamma Subunit,PDE6 Phosphodiesterases,PDE6, alpha Subunit,PDE6, beta Subunit,PDE6, delta Subunit,Phosphodiesterase 6,Phosphodiesterase Type 6,Retinal Phosphodiesterase 6,Retinal Phosphodiesterase, alpha Subunit,Retinal Phosphodiesterase, beta Subunit,Retinal Phosphodiesterase, delta Subunit,Rod cGMP Phosphodiesterase, beta Subunit,alpha Subunit, PDE6,beta Subunit, PDE6,cGMP Phosphodiesterase delta Subunit,cGMP-PDE gamma Subunit,delta Subunit, PDE6,gamma Subunit, cGMP Phosphodiesterase,PDE6 alpha Subunit,PDE6 beta Subunit,PDE6 delta Subunit,Phosphodiesterase 6, Retinal,Phosphodiesterases, PDE6,alpha Subunit PDE6,beta Subunit PDE6,cGMP PDE gamma Subunit,delta Subunit PDE6,gamma Subunit, cGMP-PDE
D055550	Protein Stability	The ability of a protein to retain its structural conformation or its activity when subjected to physical or chemical manipulations.	Protein Stabilities,Stabilities, Protein,Stability, Protein
D020710	RGS Proteins	A large family of evolutionarily conserved proteins that function as negative regulators of HETEROTRIMERIC GTP-BINDING PROTEINS. RGS PROTEINS act by increasing the GTPase activity of the G alpha subunit of a heterotrimeric GTP-binding protein, causing it to revert to its inactive (GDP-bound) form.	Regulators of G-Protein Signaling Proteins,RGS Protein (G-Protein Signaling),Regulators of G Protein Signaling Proteins
D025941	Protein Interaction Mapping	Methods for determining interaction between PROTEINS.	Interaction Mapping, Protein,Interaction Mappings, Protein,Mapping, Protein Interaction,Mappings, Protein Interaction,Protein Interaction Mappings