Moreover, BCR coexists with Tiam1 as a Rac GEF-GAP complex to regulate spine morphogenesis and synaptic plasticity under the control of BDNF-TrkB signals [ 19].
Because cyclic nucleotides have been suggested to move through gap junctions to regulate PKA activity in oocytes in mammalian systems (Sela-Abramovich et al. 2006; Norris et al. 2009), we sought to assess directly the involvement and focus of action of the kinase in meiotic maturation in C. elegans using genetic mosaic analysis.
This genetic result rules out a model in which cyclic nucleotides must move through sheath-oocyte gap junctions to regulate meiotic maturation via PKA activity in the C. elegans germ line, as has been proposed in vertebrate systems (Anderson and Albertini 1976; Sela-Abramovich et al. 2006; Norris et al. 2008, 2009).
We suggest that the PKA-ezrin-Cx43 macromolecular complex controlling the gap junction communication constitutes a general mechanism to regulate opening of Cx43 gap junctions by phosphorylation and in response to cAMP.
And within a few months of NF1's discovery, researchers had found that its sequence was remarkably similar to a gene called GAP, which was known to regulate the system of signals that tells a cell to divide.
The biologic relevance of this posttranslational modification at multiple sites in Cx43 is complex, as phosphorylation events are thought to regulate gap junction assembly, disassembly, and channel activity.
ZO-1 was shown to regulate gap junction assembly, localization, and regulate plaque size in mammalian cell cultures (Hunter et al., 2005; Laing et al., 2005; Rhett et al., 2011).
The immediate vicinity between the AKAP docking site and the PKA phosphorylation sites in Cx43 highlights the importance of the spatial organization of available PKA activity to regulate gap junction communication with the necessary kinetics.
Other ARF GAPs have been extensively documented to regulate actin cytoskeleton.
We designated this model the 'GDI-integrated model' because the activation dynamics and ultimate output of GEFs and GAPs are integrated by GDIs to regulate Rho activity.
