Volume-regulated anion channel

Basic outline of a VRAC in RVD.
Basic role of VRAC in RVD and Cell Apoptosis. This model is simplistic as it does not account for different LRRC8 protein subunits that make up the VRACs. It has been determined by Planells-Cases et al. that different subunit composition allows for specificity of VRACs (2015). This shown process is for RVD, but VRAC is also active in the observed cell shrinkage that occurs before apoptosis through the same release of anions and organic osmolytes.

Volume-regulated anion channels (VRACs) are crucial to the regulation of cell size by transporting chloride ions and various organic osmolytes, such as taurine or glutamate, across the plasma membrane,[1] and that is not the only function these channels have been linked to. Some research has also suggested that VRACs may be water-permeable as well.[2]

The regulation of cell volume is necessary not only as a prevention against swelling or shrinkage caused by a change in the cell's environment, but also throughout all stages of a cell's life. The changing of a cell's volume, whether it be swelling or shrinkage, generally occurs without major changes, such as exocytic insertion or endocytic retrieval of the plasma membrane.[1] Instead, volume regulation mostly occurs through the transport of potassium, sodium, chloride, and organic osmolytes across the membrane.[1] The ramifications of cells not being able to regulate their volume size in relation to their environments are great as swelling leads to lysis, and shrinking eventually leads from dehydration to apoptosis.[3] The specific role that VRACs play in the regulation of cell volume specifically is regulatory volume decrease (RVD) of cells.[1]

Research of VRACs has led some to conclude that they are widely expressed in mammalian cells and that they may even be ubiquitously expressed.[4] VRACs have also been shown to participate in fundamental cellular processes other than basic volume regulation, such as cell proliferation, migration, and apoptosis.[5][6]

  1. ^ a b c d Jentsch TJ (May 2016). "VRACs and other ion channels and transporters in the regulation of cell volume and beyond". Nature Reviews. Molecular Cell Biology. 17 (5): 293–307. doi:10.1038/nrm.2016.29. PMID 27033257. S2CID 40565653.
  2. ^ Nilius B (January 2004). "Is the volume-regulated anion channel VRAC a "water-permeable" channel?". Neurochemical Research. 29 (1): 3–8. doi:10.1023/B:NERE.0000010430.23137.be. PMID 14992260. S2CID 23804455.
  3. ^ Cite error: The named reference Mongin_2016 was invoked but never defined (see the help page).
  4. ^ Nilius B, Sehrer J, Viana F, De Greef C, Raeymaekers L, Eggermont J, Droogmans G (October 1994). "Volume-activated Cl- currents in different mammalian non-excitable cell types". Pflügers Archiv. 428 (3–4): 364–71. doi:10.1007/BF00724520. PMID 7816559. S2CID 27019721.
  5. ^ Eggermont J, Trouet D, Carton I, Nilius B (December 2001). "Cellular function and control of volume-regulated anion channels". Cell Biochemistry and Biophysics. 35 (3): 263–74. doi:10.1385/CBB:35:3:263. PMID 11894846. S2CID 31821726.
  6. ^ Cite error: The named reference Inoue_2007 was invoked but never defined (see the help page).