Disease relevance of Aqp1

• Binding within the aquaporin pore cannot compensate sufficiently for dehydration of the protonic charge; there is also an electrostatic barrier in the NPA region blocking proton transport [1].
• The gene for a new bacterial aquaporin, AqpX, was cloned from the pathogenic Gram-negative bacterium BRUCELLA: abortus [2].

High impact information on Aqp1

• We present several lines of evidence that the activity of this aquaporin is regulated by phosphorylation [3].
• We conclude that MIP functions as an Aquaporin in lens, but the protein may also have other essential functions [4].
• In contrast, the third cryo-EM structure that included information from the X-ray structure of the homologous bacterial glycerol facilitator GlpF and that was subsequently refined against cryo-EM AQP1 data, shows a root mean square deviation of 0.9A from the X-ray structure in the helical backbone regions [5].
• An osmo-regulated H2O-channel, aquaporin-CHIP, from bovine red blood cell membranes was purified and reconstituted with lipids, forming two-dimensional crystalline patches that diffract to about 3.0 A resolution [6].
• CONCLUSIONS: The identity of the aquaporin, its abundance, and its membrane location suggest that it is a major pathway for fluid flow across endothelial cell membranes [7].

Biological context of Aqp1

• We report here cloning of homologous cDNA (CHIP29) from an expression cDNA library constructed from bovine ciliary epithelium poly A+ that codes a 271 amino acid, 28.8 kDa protein [8].
• Aquaporin 1 (AQP1), a six-transmembrane domain protein that functions as a water channel, is present in many fluid secreting and absorbing tissues such as kidney, brain, heart, and eye [9].
• In addition, our data reveal that atrial natriuretic peptide (ANP), a peptide hormone that plays an important role in the regulation of body fluid homeostasis, blocks the AQP1-mediated increase in water permeability [9].

Anatomical context of Aqp1

• Aquaporin-1 (AQP1), a water channel from bovine red blood cells has been deglycosylated, purified to homogeneity and crystallized in a form suitable for X-ray crystallographic study [10].
• The application of AVP to Xenopus oocytes injected with AQP1 cRNA increased the membrane permeability to water [9].
• Regulatory effect of dexamethasone on aquaporin-1 expression in cultured bovine trabecular meshwork cells [11].
• Similar results were obtained using freshly dissected bovine corneas; in addition, these images showed AQP1 distributed to the plasma membranes of keratocytes [12].
• No AQP1 staining was seen in corneal epithelium, and no staining was observed in CBCEC layers exposed to AQP3, AQP4, and AQP5 antibodies [12].

Associations of Aqp1 with chemical compounds

• When the concentration of dexamethasone was higher than 25 microg/L, the expression of AQP-1 was significantly inhibited (P < 0.05) [11].
• Differential expression of Na:K:2Cl cotransporter, glucose transporter 1, and aquaporin 1 in freshly isolated and cultured bovine corneal tissues [13].
• Confocal microscopy of CBCEC in the x, y, and z planes showed rhodamine fluorescence, indicating the presence of AQP1 antibody localized to the apical and basolateral domains of the plasma membrane, but not to the membranes of intracellular compartments or other subcellular locations [12].

Other interactions of Aqp1

• Regulation of water channel activity of aquaporin 1 by arginine vasopressin and atrial natriuretic peptide [9].

Analytical, diagnostic and therapeutic context of Aqp1

• The structure of the aquaporin-1 water channel: a comparison between cryo-electron microscopy and X-ray crystallography [5].
• Crystallization and preliminary X-ray crystallographic analysis of water channel AQP1 [10].
• Three different medium-resolution structures of the human water channel aquaporin-1 (AQP1) have been solved by cryo-electron microscopy (cryo-EM) during the last two years [5].
• Abundance of mRNA encoding AQP1, GLUT1, and NKCC was quantified by a lysate nuclease protection assay [13].

References