Aquaporin-4 is a transmembrane water channel protein, the C-terminal domain of which facing cytosol. In process investigating role aquaporin-4 with regard to intracellular trafficking, we observed that derivative aquaporin-4, in 53 amino acids had been removed (?271-323), was localized compartments, including endoplasmic reticulum, but not expressed on plasma membranes. This determined by immun...

BACKGROUND Glycerol outflow from adipocytes has been considered for a decade to be mediated by aquaporin-7, an aquaglyceroporin highly expressed in the adipose tissue. Its involvement in glycerol metabolism has been widely studied also in humans. Recent studies in different aquaporin-7 KO mice models pose two different questions 1) the exact localization of aquaporin-7 in human white adipose ti...

In the present paper we explored the capacity of yeast Saccharomyces cerevisiae as host for heterologous expression of human Aquaporin-1. Aquaporin-1 cDNA was expressed from a galactose inducible promoter situated on a plasmid with an adjustable copy number. Human Aquaporin-1 was C-terminally tagged with yeast enhanced GFP for quantification of functional expression, determination of sub-cellul...

THE PROXIMAL TUBULE REABSORBS essentially all the filtered organic solutes, most of the filtered phosphate, 80% of the filtered bicarbonate, and 60% of the filtered sodium chloride. Approximately 70% of the filtered water is also reabsorbed by this segment. Despite these very high rates of proximal tubule solute transport, the osmolality of the luminal fluid decreases by only 5 mosmol/kgH2O fro...

Aquaporin-1, a ubiquitous water channel membrane protein, is a major contributor to cell membrane osmotic water permeability. Arteries are the physiological system where hydrostatic dominates osmotic pressure differences. In the present study, we show that the walls of large conduit arteries constitute the first example where hydrostatic pressure drives aquaporin-1-mediated transcellular/transe...

BACKGROUND Glial cells such as retinal Müller glial cells are involved in potassium ion and water homeostasis of the neural tissue. In these cells, inwardly rectifying potassium (Kir) channels and aquaporin-4 water channels play an important role in the process of spatial potassium buffering and water drainage. Moreover, Kir4.1 channels are involved in the maintenance of the negative Müller cel...

The aquaporins are molecular water channels expressed in the kidney and other organs. To investigate long-term regulation of renal expression of these water channels, we carried out immunoblotting studies using membrane fractions from rat renal cortex and medulla. Both 48-h water restriction in Sprague-Dawley rats and 5-day arginine vasopressin (AVP) infusion in Brattleboro rats caused signific...

Vesicle targeting proteins ("SNAREs") have been proposed to direct vasopressin-induced trafficking of aquaporin-2 water channels in kidney collecting ducts. A newly identified SNARE protein, SNAP-23, is proposed to mediate vesicle targeting to the plasma membrane in diverse tissues. The current studies were done to determine whether SNAP-23 is expressed in collecting ducts with an intracellular...

Aquaporins (AQPs) are membrane channel proteins which facilitate the rapid transport of water across cellular membrane and are of fundamental importance to the control of cell volume and transcellular water traffic. In the present study using bioinformatic tools an in silico modeling and analysis of aquaporin protein sequences of catfish Heteropneustes fossilis was conducted. Primary structure ...