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L de Lecea

Publications and source records attributed to L de Lecea.

40 records · Page 3Linked to original sources
PubMed1993

A novel adenylyl cyclase-activating serotonin receptor (5-HT7) implicated in the regulation of mammalian circadian rhythms.

We report the cloning and characterization of a novel serotonin receptor, designated as 5-HT7, which is coupled to the stimulation of adenylyl cyclase. 5-HT7 mRNA is expressed discretely throughout the CNS, predominantly in the thalamus and hypothalamus. 5-HT7 has a unique pharmacological profile that redefines agonist and antagonist classification of ligands previously thought to be "selective." The circadian phase of spontaneous neuronal activity of the rat suprachiasmatic nucleus of the hypothalamus advances in response to serotonin ligands with a pharmacological profile consistent exclusively with that of 5-HT7. These findings suggest a physiological role in the regulation of circadian rhythms for one subtype of serotonin receptor, 5-HT7, and provide a pharmacological test to evaluate its role in other neuronal systems.

Adenylyl Cyclases↗
PubMed1993

Molecular approach to hypothalamic rhythms: isolation of novel indoleamine receptor genes.

We have utilized polymerase chain reaction with primers corresponding to conserved amino acid sequences within membrane-spanning regions of known serotonin receptors to identify clones of four putative new indoleamine receptors. We have determined complete amino acid sequences of these four receptors, which fall into three subfamilies; two of these subfamilies are novel. The sites of expression within the brain have been determined for each of the genes. Expression in mammalian cells demonstrates that each new protein is a receptor for serotonin and that each has a distinct pharmacology when compared to known receptors. Two of the new receptors are coupled to cyclic adenosine monophosphate, one negatively (Gi) and one positively (Gs). The latter is a candidate for the serotonin receptor that mediates phase advances in circadian rhythms of the suprachiasmatic nucleus.

Animals↗
PubMed1992

Cloning and sequencing of a cDNA encoding 2,3-bisphosphoglycerate-independent phosphoglycerate mutase from maize. Possible relationship to the alkaline phosphatase family.

The primary sequence of maize 2,3-bisphosphoglycerate-independent phosphoglycerate mutase was deduced from cDNAs isolated from maize cDNA libraries by screening with specific antibodies to the cofactor-independent enzyme and from a maize genomic clone. The genomic clone provided the 5'-nucleotide sequence encoding the N-terminal amino acids which could not be obtained from the cDNA. Confirmation that the nucleotide sequence was for the cofactor-independent phosphoglycerate mutase was obtained by sequencing the peptides generated from cyanogen bromide cleavage of the purified protein. This is the first report of the amino acid sequence of a 2,3-bisphosphoglycerate cofactor-independent phosphoglycerate mutase, which consists of 559 amino acids and is twice the molecular size of the mammalian cofactor-dependent enzyme subunit. Analysis of the cofactor-independent phosphoglycerate mutase amino acid sequence revealed no identity with the cofactor-dependent mutase types. Northern blot analysis confirmed this difference since the maize cofactor-independent phosphoglycerate mutase cDNA did not hybridize with mRNA of the cofactor-dependent mutase. The lack of amino acid identity between cofactor-dependent and -independent enzymes is consistent with their different catalytic mechanisms and suggests that both enzymes are unrelated evolutionarily and arose from two independent ancestral genes. However, a constellation of residues which are involved in metal ion binding in various alkaline phosphatases is conserved in the maize cofactor-independent phosphoglycerate mutase, which suggests that the enzyme is a member of the alkaline phosphatase family of enzymes.

Alkaline Phosphatase↗