protein
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
protein
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
protein
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
proteins
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
proteins
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
protein
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
protein
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
protein
DEFINITION:
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.
binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).
carrier proteins - A binding protein (See above).
plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.
transport protein - binding protein (See above).
Our laboratory has previously purified endosomes derived from the apical membrane of rat kidney inner medullary collecting ducts (IMCD) containing abundant functional AQP-2 protein. Phosphorylation of AQP-2 by cAMP-dependent protein kinase (PKA) is believed to regulate the membrane trafficking of AQP-2 within IMCD cells. Purified apical membrane endosomes contain AQP-2 that is phosphorylated by endogenous PKA and dephosphorylated by a phosphatase (Lande, MB et al. J. Biol. Chem. 271:5552, 1996. ). A combination of immunoblotting and overlay assays reveal that AQP-2 endosomes contain the regulatory subunit of type II PKA (RII), protein phosphatase 2B (PP2B or calcineurin), the § isoform of protein kinase C together with a 95 kDa PKA anchoring protein or AKAP. Affinity chromatography of Triton X-100 solubilized AQP-2 endosomal proteins on cAMP agarose permits recovery of these 4 proteins as a complex similar to a AKAP 79 signaling complex present in postsynaptic densities of hippocampal neurons (Coghlan, VM et al. Science 267:108, 1995). In similar studies (Sands, JM et al. J. Clin. Invest. 99:1399, 1997) we have identified another signaling protein, the extracellular calcium polyvalent cation sensing receptor (CaR) protein and its associated signal transduction components that are also present in AQP-2 endosomes. By sensing the ionic composition of the extracellular fluid bathing the IMCD apical membrane, CaR may regulate apical membrane trafficking in IMCD in response to alterations in AVP-elicited water transport. We conclude these data provide evidence for the existence of an apical membrane signaling complex that may regulate the apical membrane trafficking of the vasopressin-elicited water channel AQP-2 and thus modulate IMCD water permeability. Pharmacological manipulation of these apical membrane signaling components may prove of value as new therapies for nephrogenic diabetes insipidus.