cDNA for the human beta 2-adrenergic receptor: a protein with multiple membrane-spanning domains and encoded by a gene whose chromosomal location is shared with that of the receptor for platelet-derived growth factor.

We have isolated and sequenced a cDNA encoding the human beta 2-adrenergic receptor. The deduced amino acid sequence (413 residues) is that of a protein containing seven clusters of hydrophobic amino acids suggestive of membrane-spanning domains. While the protein is 87% identical overall with the previously cloned hamster beta 2-adrenergic receptor, the most highly conserved regions are the putative transmembrane helices (95% identical) and cytoplasmic loops (93% identical), suggesting that these regions of the molecule harbor important functional domains.

Cloning of the gene and cDNA for mammalian beta-adrenergic receptor and homology with rhodopsin.

The adenylate cyclase system, which consists of a catalytic moiety and regulatory guanine nucleotide-binding proteins, provides the effector mechanism for the intracellular actions of many hormones and drugs. The tissue specificity of the system is determined by the particular receptors that a cell expresses. Of the many receptors known to modulate adenylate cyclase activity, the best characterized and one of the most pharmacologically important is the beta-adrenergic receptor (beta AR).

Evidence for an increase in transcription of specific mRNAs during differentiation of 3T3-L1 preadipocytes.

Differentiation of 3T3-L1 preadipocytes in culture is accompanied by alterations in the abundance of several mRNAs and by the appearance of many new adipocyte-specific mRNAs. To investigate the processes responsible for these alterations, the kinetics of accumulation of several specific mRNAs were compared with their respective rates of nuclear runoff transcription. The mRNAs for fructose-1,6-bisphosphate aldolase and an unidentified 4800-base mRNA increase in abundance only moderately (2-4-fold) during differentiation.

Expression of specific mRNAs during adipose differentiation: identification of an mRNA encoding a homologue of myelin P2 protein.

To identify and characterize specific mRNAs that increase in abundance during differentiation of mouse 3T3-L1 preadipocytes, a cDNA library was constructed from poly(A)+RNA isolated from differentiated 3T3-L1 adipocytes. Mixed probe isotope ratio selection and RNA blot analyses have identified several unique cDNA clones that represent mRNA species expressed either exclusively or at dramatically increased levels in differentiated cells. Further characterization of one such clone (pAL422) revealed that the corresponding mRNA, detectable only after differentiation, is approximately the same length (600 +/- 150 bases) as the cDNA insert (672 bases).

Fatty acylation of proteins during development of sea urchin embryos.

Developing embryos of the sea urchin, Strongylocentrotus purpuratus, incorporate [3H]palmitic acid into at least 20 proteins. The [3H]palmitic acid associated with these proteins is released by alkaline hydrolysis or by treatment with hydroxylamine but not by extensive extraction with chloroform:methanol, indicating that the fatty acids are covalently attached to protein. The finding that the fatty acid is released by hydroxylamine or beta-mercaptoethanol at neutral or even slightly acidic pH suggests that this moiety may be attached to the polypeptide via a thiol ester bond.

Quantitative measures of aging in the nematode Caenorhabditis elegans: II. Lysosomal hydrolases as markers of senescence.

In an attempt to provide additional quantitative markers of senescence in the nematode Caenorhabditis elegans, we have identified age-dependent increases in four lysosomal enzymes: acid phosphatase, beta-N-acetyl-D-glucosaminidase, beta-D-glucosidase, and alpha-D-mannosidase. These enzymes were judged to be lysosomal on the basis of their resemblance to analogous mammalian lysosomal enzymes with regard to subcellular fractionation, lectin binding, Km, molecular weights, inhibitor sensitivities, and pH optima. In nematode populations which had a median lifespan of 8.

Quantitative measures of aging in the nematode Caenorhabditis elegans. I. Population and longitudinal studies of two behavioral parameters.

As a first step in the quantitative characterization of senescence in the nematode Caenorhabditis elegans, we have studied movement wave frequency, defecation frequency, and whole-body water efflux as a function of age. Populations of C. elegans, strain N2, were cultured monoxenically on E.