• Source: Aquaporin-2

Aquaporin-2 (AQP-2) is found in the apical cell membranes of the kidney's collecting duct principal cells and in intracellular vesicles located throughout the cell. It is encoded by the AQP2 gene.




Regulation


It is the only aquaporin regulated by vasopressin.
The basic job of aquaporin 2 is to reabsorb water from the urine while its being removed from the blood by the kidney. Aquaporin 2 is in kidney epithelial cells and usually lies dormant in intracellular vesicle membranes. When it is needed, vasopressin binds to the cell surface vasopressin receptor thereby activating a signaling pathway that causes the aquaporin 2 containing vesicles to fuse with the plasma membrane, so the aquaporin 2 can be used by the cell.
This aquaporin is regulated in two ways by the peptide hormone vasopressin:

short-term regulation (minutes) through trafficking of AQP2 vesicles to the apical region where they fuse with the apical plasma membrane
long-term regulation (days) through an increase in AQP2 gene expression.
This aquaporin is also regulated by food intake. Fasting reduces expression of this aquaporin independently of vasopressin.




Clinical significance


Mutations in this channel are associated with nephrogenic diabetes insipidus, which can be autosomal dominant or recessive. Mutations in the vasopressin receptor cause a similar X-linked phenotype.
Lithium, which is often used to treat bipolar disorder, can cause acquired diabetes insipidus (characterized by the excretion of large volumes of dilute urine) by decreasing the expression of the AQP2 gene.
The expression of the AQP2 gene is increased during conditions associated with water retention such as pregnancy and congestive heart failure.




See also


Aquaporin




References






Further reading






External links


GeneReviews/NCBI/NIH/UW entry on Nephrogenic Diabetes Insipidus
Aquaporin+2 at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
Human AQP2 genome location and AQP2 gene details page in the UCSC Genome Browser.
Overview of all the structural information available in the PDB for UniProt: P41181 (Aquaporin-2) at the PDBe-KB.

Kata Kunci Pencarian:

• Akuaporin 2
• Akuaporin 3
• Akuaporin
• Demeklosiklin
• Akuaporin 1
• Akuaporin 4
• Akuagliseroporin
• Ginjal
• Caveolin 1
• Fitoremediasi Merkuri
• Aquaporin-2
• Aquaporin
• Aquaporin-3
• Vasopressin
• Diabetes insipidus
• Nephrogenic diabetes insipidus
• Syndrome of inappropriate antidiuretic hormone secretion
• Aquaporin-4
• Loop of Henle
• Kidney