Recent observations have also implicated gap junction functions in neutrophil transendothelial migration [ 16].
FAM13A is an interesting candidate gene because of the Rho-GAP domain it encodes 23 and its associated tumor suppressor activity through inhibition of the intracellular signal transduction molecule Rho A. 24 This Rho-GAP activity implicates FAM13A in carcinogenesis.
Moreover, the small GTPases Rab11 and Rab4, as well as a Rab-GAP, have been implicated in mediating translocation of the glucose importer GLUT4 to the plasma membrane upon insulin stimulation [ 21, 22].
In addition, GAPs have been implicated in Arf1 recruitment to cargo, SNAREs and coat components; in case of the yeast ArfGAP2/3 Glo3 through the BoCCS region (Lanoix et al., 2001; Rein et al., 2002; Schindler et al., 2009).
Barker et al. [ 86] revealed that association between ZO-1 and Cx43 is increased during remodeling of cardiac gap junctions, possibly implicating ZO-1 in gap junction turnover during cardiac development and possibly during disease progress.
Gap junctions are also implicated in cell death.
The epidermis expresses a number of connexin (Cx) proteins that are implicated in gap junction-mediated cell communication.
Cell-to-cell communication via gap junctions has been implicated in the control of vascular tone and may be altered in sepsis.
Alteration of cell-to-cell communication via gap junctions has been implicated in the tumorigenic process and is supported by considerable evidence (Trosko and Ruch 2002).
Transient opening of Cx43 hemichannels that lie free in the plasma membrane, external to gap junctions, has been implicated in cell swelling, ATP release, and loss of membrane potential during ischaemia, though the presence of pannexin rather than connexin hemichannels has been suggested as an alternative explanation for such phenomena.
