Pannexins are comprised of four transmembrane segments, two extra-cellular loops and both the amino and carboxi termini are facing the cytosol. Pannexins also have four conserved extracellular loop cysteines resulting in the possibility of two intra-pannexin disulfide bonds. Pannexin 3 has a glycosylation site at N254 and N71. Pannexin membrane channels are formed by 6-8 monomers and while Pannexin’s 3 exact oligomeric number has not been determined yet it is expected to be 6 with a greater similarity to Pannexin 1 than 2 .nThere are two known subtypes of Panx3 in mice with different molecular weight and distribution. The first, weighing 43 kDa is mostly expressed in cartilage skin tissues and also in low levels in heart ventricle tissue. The second, weighing 70 kDa, and possibly functioning as a dimer is detected in lung, liver, thymus and spleen tissues.Since full understanding of Pannexin 3 structure, expression and role in physiological and pathological tissues is yet to be obtained there is a definite need for further research.
