Cannabinoid receptor interacting protein 1a interacts with myristoylated Gαi N terminus via a unique gapped β-barrel structure
| Autor: | Sandra Leone-Kabler, Khalil Eldeeb, W. Todd Lowther, William T. Booth, Erin K. Hughes, Jill E. Clodfelter, Allyn C. Howlett |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
CB1R
CB1 receptor Cell signaling Accelerated Communication CRIP1a cannabinoid receptor interacting protein 1a Protein Conformation Peptide Small G Protein GTP-Binding Protein alpha Subunits Gi-Go Antiparallel (biochemistry) Biochemistry FABP fatty acid–binding protein Mice Receptor Cannabinoid CB1 T4L T4 lysozyme guanine nucleotide dissociation inhibitor small G proteins Animals Amino Acid Sequence endocannabinoid system fatty acid–binding protein Receptors Cannabinoid Molecular Biology G protein-coupled receptor Myristoylation Adaptor Proteins Signal Transducing chemistry.chemical_classification PDE6δ phosphodiesterase 6 delta subunit Chemistry Cannabinoids G protein–coupled receptors BRIL b562RIL Membrane Proteins Cell Biology Editors' Pick GDI guanine nucleotide dissociation inhibitor N-terminus Biophysics lipids (amino acids peptides and proteins) Threading (protein sequence) Carrier Proteins Peptides Endocannabinoids Protein Binding |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X 0021-9258 |
| Popis: | Cannabinoid receptor interacting protein 1a (CRIP1a) modulates CB1 cannabinoid receptor G-protein coupling in part by altering the selectivity for Gαi subtype activation, but the molecular basis for this function of CRIP1a is not known. We report herein the first structure of CRIP1a at a resolution of 1.55 A. CRIP1a exhibits a 10-stranded and antiparallel β-barrel with an interior comprised of conserved hydrophobic residues and loops at the bottom and a short helical cap at the top to exclude solvent. The β-barrel has a gap between strands β8 and β10, which deviates from β-sandwich fatty acid–binding proteins that carry endocannabinoid compounds and the Rho-guanine nucleotide dissociation inhibitor predicted by computational threading algorithms. The structural homology search program DALI identified CRIP1a as homologous to a family of lipidated-protein carriers that includes phosphodiesterase 6 delta subunit and Unc119. Comparison with these proteins suggests that CRIP1a may carry two possible types of cargo: either (i) like phosphodiesterase 6 delta subunit, cargo with a farnesyl moiety that enters from the top of the β-barrel to occupy the hydrophobic interior or (ii) like Unc119, cargo with a palmitoyl or a myristoyl moiety that enters from the side where the missing β-strand creates an opening to the hydrophobic pocket. Fluorescence polarization analysis demonstrated CRIP1a binding of an N-terminally myristoylated 9-mer peptide mimicking the Gαi N terminus. However, CRIP1a could not bind the nonmyristolyated Gαi peptide or cargo of homologs. Thus, binding of CRIP1a to Gαi proteins represents a novel mechanism to regulate cell signaling initiated by the CB1 receptor. |
| Databáze: | OpenAIRE |
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