Myristoylation of an inhibitory GTP-binding protein. alpha. subunit is essential for its membrane attachment

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.87.2.568· OSTI ID:6700184

Jones, T L.Z.; Simonds, W F; Merendino, Jr, J J; Brann, M R; Spiegel, A M ^[1]

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1. National Institutes of Health, Bethesda, MD (USA)

The authors transfected COS cells with cDNAs for the {alpha} subunits of stimulatory and inhibitory GTP-binding proteins, {alpha}{sub s} and {alpha}{sub i1}, respectively, and immunoprecipitated the metabolically labeled products with specific peptide antibodies. Cells were separated into particulate and soluble fractions before immunoprecipitation; ({sup 35}S)methionine-labeled {alpha}{sub s} and {alpha}{sub i} were both found primarily in the particulate fraction. ({sup 3}H)Myristate was incorporated into endogenous and transfected {alpha}{sub i} but could not be detected in {alpha}{sub s} even when it was overexpressed. They converted the second residue, glycine, of {alpha}{sub i1} into alanine by site-directed mutagenesis. Upon transfection of the mutant {alpha}{sub i1} into COS cells, the ({sup 35}S)methionine-labeled product was localized primarily to the soluble fraction, and, also unlike normal {alpha}{sub i1}, the mutant failed to incorporate ({sup 3}H)myristate. The unmyristoylated mutant {alpha}{sub i1} could still interact with the {beta}-{gamma} complex, since purified {beta}{gamma} subunits promoted pertussis toxin-catalyzed ADP-ribosylation of both the normal and mutant {alpha}{sub i1} subunits. These results indicate that myristoylation is critical for membrane attachment of {alpha}{sub i} but not {alpha}{sub s} subunits.

• OSTI ID: 6700184
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 87:2; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALANINES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
ANTIBODIES
ANTIGENS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
DNA
DRUGS
ELECTROPHORESIS
EVEN-ODD NUCLEI
GLYCINE
HYDROGEN COMPOUNDS
IMMUNOLOGY
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
MATERIALS
METHIONINE
MOLECULAR STRUCTURE
MONOCARBOXYLIC ACIDS
MUTAGENESIS
NUCLEI
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
POLYMERIZATION
PRECIPITATION
PROTEINS
PURIFICATION
RADIOISOTOPES
RATS
RECOMBINANT DNA
RODENTS
SEPARATION PROCESSES
SUBCELLULAR DISTRIBUTION
SULFUR 35
SULFUR ISOTOPES
TETRADECANOIC ACID
TOXIC MATERIALS
TOXINS
TRITIUM COMPOUNDS
VERTEBRATES