Individual S-acylated cysteines differentially contribute to H-Ras endomembrane trafficking and acylation/deacylation cycles.
S-acylation/deacylation cycles and vesicular transport are critical for an adequate subcellular distribution of S-acylated Ras proteins. H-Ras is dually acylated on cysteines 181 and 184, but it is unknown how these residues individually contribute to H-Ras trafficking. In this study, we characterized the acylation and deacylation rates and membrane trafficking of monoacylated H-Ras mutants to analyze their contributions to H-Ras plasma membrane and endomembrane distribution. We demonstrated that dually acylated H-Ras interacts with acyl-protein thioesterases (APTs) 1 and 2 at the plasma membrane. Moreover, single-acylation mutants of H-Ras differed not only in their subcellular distribution, where both proteins localized to different extents at both the Golgi complex and plasma membrane, but also in their deacylation rates, which we showed to be due to different sensitivities to APT1 and APT2. Fluorescence photobleaching and photoactivation experiments also revealed that 1) although S-acylated, single-acylation mutants are incorporated with different efficiencies into Golgi complex to plasma membrane vesicular carriers, and 2) the different deacylation rates of single-acylated H-Ras influence differentially its overall exchange between different compartments by nonvesicular transport. Taken together, our results show that individual S-acylation sites provide singular information about H-Ras subcellular distribution that is required for GTPase signaling.
Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, and Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina.
Maria P
MP
Pedro
Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, and Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina.
Aldo A
AA
Vilcaes
Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, University of Queensland, St. Lucia, QLD 4072, Australia.
Guillermo A
GA
Gomez
Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, and Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA, Córdoba, Argentina daniotti@fcq.unc.edu.ar.
Jose L
JL
Daniotti
D000215:Acylation; D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism* / Q000502:physiology; D003412:Cricetulus; D003545:Cysteine / Q000378:metabolism; D011905:Genes, ras / Q000502:physiology*; D006056:Golgi Apparatus / Q000378:metabolism; D009154:Mutation; D021381:Protein Transport / Q000502:physiology*; D011506:Proteins / Q000378:metabolism; D015398:Signal Transduction; D013869:Thiolester Hydrolases / Q000378:metabolism
D011506:Proteins; D013869:Thiolester Hydrolases; D003545:Cysteine