G-protein-coupled receptors

DEFINITION:

G-proteins are proteins embedded in the surface membrane of cells. These proteins "receive chemical signals" from outside the cell (e.g., hormones) and "pass the signal" into the cell, so that the cell can "respond to the signal." For example, a hormone, drug, neurotransmitter, or other "signal" binds to a receptor molecule on the surface of the cell's exterior membrane. That receptor then activates the G-protein, which causes an effector inside the cell to produce a second "signal" chemical inside the cell, which causes the cell to react to the original external chemical signal.

GPCRs

DEFINITION:

G-protein-coupled receptors.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

clathrin

DEFINITION:

A 180,000-dalton protein that coats the cytoplasmic face of coated pits involved in receptor-mediated endocytosis of low-density lipoprotein (LDL), insulin, and other ligands.

ubiquitination

DEFINITION:

See ubiquitin .

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

affinity

DEFINITION:

1. A special attraction for a specific element, organ, or structure.

2. Chemical affinity.

3. In immunology, a thermodynamic expression of the strength of interaction between a single antigen-binding site and a single antigenic determinant (and thus of the stereochemical compatibility between them), most accurately applied to interactions among simple, uniform antigenic determinants such as haptens. Expressed as the association constant (K liters mole^-1), which, owing to the heterogeneity of affinities in a population of antibody molecules of a given specificity, actually represents an average value (mean intrinsic association constant).

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

GPCRs

DEFINITION:

G-protein-coupled receptors.

G

DEFINITION:

As G - Symbol for "gauss," "giga-," "gravida," and "guanine" or "guanosine."

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

receptors

DEFINITION:

See definitions under "receptor."

G

DEFINITION:

As G - Symbol for "gauss," "giga-," "gravida," and "guanine" or "guanosine."

V2

DEFINITION:

Vasopressin-2. See vasopressin-2 gene and vasopressin-2 receptor.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

receptors

DEFINITION:

See definitions under "receptor."

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

endosomes

DEFINITION:

Distinct intracellular compartments isolated from the rest of the cell by selectively permeable membranes. On their way to lysosomes, endocytosed material must first pass through a series of these endosomal compartments. See endocytosis.

V2R

DEFINITION:

Vasopressin-2 receptor.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

ubiquitination

DEFINITION:

See ubiquitin .

ubiquitination

DEFINITION:

See ubiquitin .

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

correlate

DEFINITION:

To connect in a systematic way; establish the mutual relations of. See also correlation .

association

DEFINITION:

1. A state in which two attributes occur together either more or less often than expected by chance.

2. In neurology, a term applied to those regions of the brain that link the primary motor and sensory cortices; see association areas.

3. In genetics, the occurrence together of two or more phenotypic characteristics more often than would be expected by chance.

4. In psychiatry, a connection between ideas or feelings, especially between conscious thoughts and elements of the unconscious, or the formation of such a connection.

dissociation

DEFINITION:

1. The act of separating or state of being separated.

2. The separation of a molecule into two or more fragments (atoms, molecules, ions, or free radicals) produced by the absorption of light or thermal energy or by solvation.

3. Segregation of a group of mental processes from the rest of a person's usually integrated functions of consciousness, memory, perception, and sensory and motor behavior, as in the separation of the personality and aspects of memory or subpersonalities in the dissociative disorders or in the segregation of an idea or object from its emotional significance, as is sometimes seen in schizophrenia.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

constructed

DEFINITION:

Built, made.

cytoplasmic

DEFINITION:

Pertaining to or contained in the cytoplasm.

receptors

DEFINITION:

See definitions under "receptor."

V2

DEFINITION:

Vasopressin-2. See vasopressin-2 gene and vasopressin-2 receptor.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

receptors

DEFINITION:

See definitions under "receptor."

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

trafficking

DEFINITION:

Acting as a transporter.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

ubiquitination

DEFINITION:

See ubiquitin .

functional

DEFINITION:

1. Of or pertaining to a function.

2. Affecting the function but not the structure.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

ubiquitination

DEFINITION:

See ubiquitin .

constructed

DEFINITION:

Built, made.

chimera

DEFINITION:

An individual organism whose body contains cell populations derived from different zygotes, of the same or of different species; it may occur spontaneously, as in twins (blood group chimeras), or be produced artificially, as an organism that develops from combined portions of different embryos, or one in which tissues or cells of another organism have been introduced.

ubiquitinated

DEFINITION:

See ubiquitin .

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

dissociate

DEFINITION:

See dissociation .

internalized

DEFINITION:

Describing the mental process whereby certain attributes, attitudes, or standards of others are unconsciously taken as one's own.

endosomes

DEFINITION:

Distinct intracellular compartments isolated from the rest of the cell by selectively permeable membranes. On their way to lysosomes, endocytosed material must first pass through a series of these endosomal compartments. See endocytosis.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

trafficking

DEFINITION:

Acting as a transporter.

degradation

DEFINITION:

1. The act or process of impairing in respect to some physical property.

2. The reduction of a chemical compound to one less complex, as by splitting off one or more groups.

NEM

DEFINITION:

N-Ethylmaleimide.

inhibitor

DEFINITION:

1. Any substance that interferes with a chemical reaction, growth, or other biological activity.

2. A chemical substance that inhibits an enzyme reaction.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

dissociation

DEFINITION:

1. The act of separating or state of being separated.

2. The separation of a molecule into two or more fragments (atoms, molecules, ions, or free radicals) produced by the absorption of light or thermal energy or by solvation.

3. Segregation of a group of mental processes from the rest of a person's usually integrated functions of consciousness, memory, perception, and sensory and motor behavior, as in the separation of the personality and aspects of memory or subpersonalities in the dissociative disorders or in the segregation of an idea or object from its emotional significance, as is sometimes seen in schizophrenia.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

ubiquitination

DEFINITION:

See ubiquitin .

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

trafficking

DEFINITION:

Acting as a transporter.

beta-arrestin

DEFINITION:

An inhibitory protein which blocks the receptor's ability to activate the stimulatory G protein G_s.

permission

DEFINITION:

Formal consent; authorization.