Recombinant MouseAquaporin-4 (Aqp4), partial

Function

Forms a water-specific channel (PubMed:18286643, PubMed:8660998, PubMed:9276712). Plays an important role in brain water homeostasis and in glymphatic solute transport (PubMed:22896675, PubMed:27751903, PubMed:30557661, PubMed:30561329). Required for a normal rate of water exchange across the blood brain interface (PubMed:30557661). Required for normal levels of cerebrospinal fluid influx into the brain cortex and parenchyma along paravascular spaces that surround penetrating arteries, and for normal drainage of interstitial fluid along paravenous drainage pathways. Thereby, it is required for normal clearance of solutes from the brain interstitial fluid, including soluble beta-amyloid peptides derived from APP (PubMed:22896675, PubMed:27751903, PubMed:30561329). Plays a redundant role in urinary water homeostasis and urinary concentrating ability (PubMed:9276712)

Subcellular Location

Cell membrane (Multi-pass membrane protein); Basolateral cell membrane (Multi-pass membrane protein); Endosome membrane; Cell membrane, sarcolemma (Multi-pass membrane protein); Cell projection

Tissue Specificity

Detected in brain cortex, especially around cortical blood vessels, and subjacent to pia, with lower levels in parenchymal membranes (PubMed:27751903). Detected in ependymal and astroglial cells in brain (PubMed:22896675, PubMed:27751903, PubMed:8660998, PubMed:9276712). Detected in supporting Hensen's cells, inner sulcus cells and Claudius cells in the inner ear (PubMed:11406631). Detected in skeletal muscle (PubMed:29055082). Detected in gastric parietal cells (PubMed:10915655). Detected in principal cells in collecting ducts in kidney medulla (at protein level) (PubMed:16641094, PubMed:9276712). Detected in brain, heart and skeletal muscle (PubMed:8660998)

Subunit

Homotetramer. The tetramers can form oligomeric arrays in membranes. The size of the oligomers differs between tissues and is smaller in skeletal muscle than in brain. Interaction between AQP4 oligomeric arrays in close-by cells can contribute to cell-cell adhesion (By similarity). Part of a complex containing MLC1, TRPV4, HEPACAM and ATP1B1 (By similarity)

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• Turtzo L.C. et al. Cloning and chromosomal localization of mouse aquaporin 4: exclusion of a candidate mutant phenotype, ataxia. — Genomics (1997)
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• Ebert L. et al. Cloning of mouse full open reading frames in Gateway(R) system entry vector (pDONR201). (JUL-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
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• Li J. et al. Impaired hearing in mice lacking aquaporin-4 water channels. — J. Biol. Chem. (2001)