Metazoan membrane bound ACs are composed of two membrane domains, each consisting of six transmembrane helices.
NOX2 is composed of two membrane bound subunits, p22phox and gp91phox (the catalytic unit), and three cytosolic subunits, p47phox, p67phox, and p40phox.
The functional NADPH oxidase complex is composed of two membrane bound (gp91phox and gp22phox) and two structural cytosolic proteins (gp47phox and gp67phox).
One has a typical ABC transporter structure and is composed of two membrane spanning domains (MSD) with nucleotide binding domains (NBD1 and NBD2) in between.
The NADPH oxidase complex in VSMCs is composed of two membrane subunits, NOX2/gp91 phox and p22 phox, and four cytosolic subunits, p40 phox, p47 phox, p67 phox and Rac1 [ 11, 12].
The export apparatus is located at the bottom of the MS ring and is composed of six membrane proteins (FlhA, FlhB, FliP, FliQ, FliR, and FliO) and three soluble proteins (FliI, FliH, and FliJ) in the cytoplasm.
EGF ligands bind to a complex system of cell surface receptors, termed the ErbB system, composed of four membrane-associated proteins, ErbB1 (also known as EGFR), ErbB2 (an orphan receptor), ErbB3 and ErbB4.
Originally discovered in barley [ 4] and subsequently found in many plant species [ 5], CNGCs share a Shaker-like structure composed of six membrane-spanning domains (S1-6) with a pore situated between S5 and S6 [ 3, 6].
