Mice with targeted disruption of the acyl-CoA binding protein display attenuated urine concentrating ability and diminished renal aquaporin-3 abundance

Bill

Molecular Membrane Biology

2012

Water can pass through the cell membrane relatively slowly by diffusion. However, in order to maintain water homeostasis, the rapid and specific regulation of cellular water flow is mediated by the aquaporin (AQP) family of membrane protein water channels. Thirteen human AQPs have been identified to date and the majority are highly specific for water while others show selectivity for water, glycerol and other small solutes. The wide range of tissues that are known to express AQPs is reflected by their involvement in many physiological processes and diseases. Receptor mediated translocation, via hormone activation, is an established method of AQP regulation, especially for AQP2. There is now an emerging consensus that the rapid and reversible translocation of other AQPs from intracellular vesicles to the plasma membrane, triggered by a range of stimuli, can confer increased membrane permeability. This review examines new advances that have identified molecular mechanisms of AQP regulation; these include the role of cytoskeletal proteins, kinases, calcium and retention or localisation signals as well as specific triggers of AQP translocation. This article reviews current knowledge of AQP regulation with a focus on rapid and dynamic regulation of sub-cellular AQP translocation in response to a specific trigger.3

Section: Localisation and Retention Signalsmentioning

confidence: 70%

An emerging consensus on aquaporin translocation as a regulatory mechanism

Bill

Molecular Membrane Biology

2012

“…Rabbit anti-AQP4, 249-323 (Alomone) has been used in a number of publications, e.g., Ref. ( 42 ). Rabbit anti-AQP7, 1246, has been characterized with the use of knockout animals ( 43 , 44 ).…”

Section: Methodsmentioning

confidence: 99%

Characterization of AQPs in Mouse, Rat, and Human Colon and Their Selective Regulation by Bile Acids

Yde

Keely

et al. 2016

Front. Nutr.

In normal individuals, the epithelium of the colon absorbs 1.5–2 l of water a day to generate dehydrated feces. However, in the condition of bile acid malabsorption (BAM), an excess of bile acids in the colon results in diarrhea. Several studies have attempted to address the mechanisms contributing to BAM induced by various bile acids. However, none have addressed a potential dysregulation of aquaporin (AQP) water channels, which are responsible for the majority of transcellular water transport in epithelial cells, as a contributing factor to the onset of diarrhea and the pathogenesis of BAM. In this study, we aimed to systematically analyze the expression of AQPs in colonic epithelia from rat, mouse, and human and determine whether their expression is altered in a rat model of BAM. Mass spectrometry-based proteomics, RT-PCR, and western blotting identified various AQPs in isolated colonic epithelial cells from rats (AQP1, 3, 4, 7, 8) and mice (AQP1, 4, 8). Several AQPs were also detected in human colon (AQP1, 3, 4, 7–9). Immunohistochemistry localized AQP1 to the apical plasma membrane of epithelial cells in the bottom of the crypts, whereas AQP3 (rat, human) and AQP4 (mice, human) were localized predominantly in the basolateral plasma membrane. AQP8 was localized intracellularly and at the apical plasma membrane of epithelial cells. Rats fed sodium cholate for 72 h had significantly increased fecal water content, suggesting development of BAM-associated diarrhea. Colonic epithelial cells isolated from this model had significantly altered levels of AQP3, 7, and 8, suggesting that these AQPs may be involved in the pathogenesis of bile acid-induced diarrhea.

Journal of Lipid Research

“…Mice with targeted disruption of the ACBP gene were generated as described ( 24,29 ). Mice carrying the targeted ACBP gene were identifi ed using primer pairs i ) 5 ′ -AGG ATC TCC TGT CAT CTC ACC TTG CTC CTG and 5 ′ -AAG AAC TCG TCA AGA AGG CGA TAG AAG GCG ( ‫ف‬ 500 bp fragment within the neo R cassette) and ii ) 5 ′ -AGG ATC TCC TGT CAT CTC ACC TTG CTC CTG and 5 ′ -GTA TCT GCT CAT CTA TTC GGC TTG G ( ‫ف‬ 1,200 bp fragment spanning the 3 ′ region of the neo R cassette to the 5 ′ region of intron 2).…”

Section: Generation Of Acbp-defi Cient Micementioning

confidence: 99%

The acyl-CoA binding protein is required for normal epidermal barrier function in mice

Bloksgaard

Bek

Marcher

et al. 2012

Self Cite

This article is available online at http://www.jlr.org Supplementary key words stratum corneum • very long chain fatty acids • mono alkyl diacyl glycerol • transepidermal water loss • multiphoton excitation microscopy • lipid mass spectrometryThe acyl-CoA binding protein (ACBP)/diazepam binding inhibitor (DBI) (Entrez Gene ID: 13167) is a 10 kDa intracellular protein that specifi cally binds medium and long chain acyl-CoA esters (C 14 -C 22 ) with very high affi nity (K d ‫ف‬ 1-10 nM) ( 1, 2 ). The protein is expressed in all eukaryotic species and in all mammalian tissues investigated ( 3-5 ); however, expression levels differs markedly between different tissues and cell types examined, with particularly high levels in epithelial cell types and in cells with a high turn-over of fatty acids (FA) ( 6 ). Consistently with this, we have shown that the ACBP gene is activated by lipogenic transcription factors, such as the peroxisome proliferatoractivated receptor ␥ ( 7 ) and members of the sterol-regulatory element binding protein family ( 7-10 ). In vitro studies indicate that ACBP plays a role in transport of acyl-CoA esters and may deliver acyl-CoA esters to phospholipid