AQP4
AQP4 (aquaporin-4, also known as MIWC, AQP-4 and hAQP4) is a water-specific channel of the MIP/aquaporin family. It is the predominant aquaporin in brain and plays an important role in brain water homeostasis. Browse Assay Genie's current range of AQP4 research reagents below, or read on for the biology behind the target.
AQP4 forms a water-specific channel in the plasma membrane. It is required for a normal rate of water exchange across the blood brain interface and is involved in glymphatic solute transport. The protein is needed 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 pathways. Through these routes it contributes to the clearance of solutes from brain interstitial fluid, including soluble beta-amyloid peptides derived from APP. In contrast, AQP4 plays a redundant role in urinary water homeostasis and urinary concentrating ability.
The AQP4 gene encodes a member of the aquaporin family of intrinsic membrane proteins, which act as water-selective channels in the plasma membranes of many cells. The AQP4 protein is the predominant aquaporin found in brain. UniProt records it at the cell membrane, including the basolateral cell membrane and the sarcolemma, as well as in endosome membranes and cell projections. The protein belongs to the MIP/aquaporin family (TC 1.A.8), and HGNC places the gene in the aquaporins group.
The gene is notable for its range of products. Alternatively spliced transcript variants encoding different isoforms have been described, as have additional isoforms arising from alternative in-frame translation initiation codons. Recent studies also provided evidence for translational readthrough, with expression of C-terminally extended isoforms through use of an alternative in-frame termination codon. Mouse and rat both carry an Aqp4 ortholog, so the protein can be studied in common rodent models.
AQP4 is the predominant aquaporin in brain and has an important role in maintaining brain water homeostasis.
AQP4 is involved in glymphatic solute transport and in cerebrospinal fluid influx along paravascular spaces around penetrating arteries.
AQP4 is required for normal clearance of solutes from brain interstitial fluid, including soluble beta-amyloid peptides derived from APP.
AQP4 is required for a normal rate of water exchange across the blood brain interface.
AQP4 forms a water-specific channel in the cell membrane. It is important for brain water homeostasis, water exchange across the blood brain interface and glymphatic solute transport. It has a redundant role in urinary water homeostasis and urinary concentrating ability.
AQP4 is also called MIWC, AQP-4 and hAQP4, and its full name is aquaporin 4. Alternatively spliced variants and alternative in-frame translation initiation give different isoforms, and translational readthrough can produce C-terminally extended isoforms.
Mouse and rat each have an Aqp4 ortholog. Within humans, AQP4 belongs to the MIP/aquaporin family alongside other water channels such as AQP1 and AQP2. Check the datasheet of any product for its validated reactivity.
Other members of the aquaporin family of water channels with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P55087; product specifications from Assay Genie datasheets.