What Are Aquaporins?
Aquaporin, also known as aquaporin, is a protein (intrinsic membrane protein) located on the cell membrane, which forms a "pore channel" on the cell membrane, which can control the ingress and egress of water in the cell, just like "the cell's water pump" "same.
- Aquaporin, also known as aquaporin, is a protein located on the cell membrane (
- Agre et al. (1988) in
AQP0 Aquaporin AQP0
- AQP0 was originally called major intrinsic protein (MIP). It is abundantly expressed in cells of lens fibers and is related to the transparency of the lens. AQpo mutations can cause lens edema and cataracts. Lack of AQPO in mice will cause congenital cataracts .
AQP1 Aquaporin AQP1
- AQP1 was discovered in 1988 and began to call this protein channel-forming integrin (CHIP), which is a component of human red blood cell membranes.
- Major proteins. It allows red blood cells to rapidly expand and contract to adapt to changes in cell-to-cell permeability. AQP1 protein is also present in
- In other tissues. AQP1 and its homologues allow water to pass freely (without binding), but do not allow ions or other
- Of small molecules (including proteins).
- AQP1 is composed of four identical subunits, each with a relative molecular mass of 28 kDa, and each subunit has six transmembrane structures
- Domain, there is a ring structure between transmembrane domains 2 and 3, 5 and 6, which is the channel through which water passes. In addition, the amino and carboxyl ends of AQP1
- The amino acid sequence is strictly symmetrical. Therefore, the homologous transmembrane regions (1, 4, 2, 5, 3, 6) have opposite directions in the lipid bilayer of the plasma membrane. AQP1
- The permeability to water is inhibited by the reversibility of mercury chloride, and the sensitive site for mercury is the cysteine at position 189 between domains 5 and 6. its
- Several types of AQP1 are related to renal function.
- Professor Peter Agre wins 2003 Nobel Prize for chemistry for discovering aquaporins
- AQPl exists as a tetramer in the plasma membrane, and each monomer consists of 6 long a-helixes that run through both sides of the membrane to form the basic skeleton, with two short a-helixes embedded but not penetrating the membrane . The hollow part of each monomer protein forms a highly selective channel, which allows only water molecules to be transported across the membrane and does not allow charged protons or other ions to pass. It can function as an independent water channel.
- Aquaporins in mammals
- There are currently 13 known aquaporins in mammals, six of which are located in the kidney, but scientists still have doubts about the existence of other aquaporins. The most concerned aquaporins are compared as follows: