Disease relevance of GJA8

• METHODS: Recombinant retroviruses expressing three chick lens connexins (Cx)-Cx43, Cx45.6, and Cx56-were prepared and used to infect isolated chick lens primary cultures [1].

High impact information on GJA8

• Our previous studies show that MIP(AQP0) associates with gap junction plaques formed by Cx45.6 and Cx56 during the early stages of embryonic chick lens development but not in late embryonic and adult lenses [2].
• Surface plasmon resonance experiments indicated that the C-terminal domain of MIP(AQP0) interacts with two binding sites within the intracellular loop region of Cx45.6 with a K(D(app)) of 7.5 and 10.3 microm, respectively [2].
• Finally, caspase-3-mediated cleavage can be regulated by casein kinase II-mediated phosphorylation, suggesting that Cx45.6 turnover and specific cleavage by caspase-3-like protease is alternatively modulated [3].
• When isolated lens membranes were treated by caspase-3, the truncated fragments of Cx45.6 were reproduced, and this truncation occurred at the COOH terminus of Cx45 [3].
• Our peptide mapping experiments showed that the Ser(363) site in the carboxyl (COOH) terminus of Cx45.6 was phosphorylated and that this site is within casein kinase (CK) II consensus sequence, although showing some similarity to CKI sequence [4].

Biological context of GJA8

• Stimulation of lens cell differentiation by gap junction protein connexin 45.6 [1].
• The lentoids, a unique morphologic structure that is an indicative of lens fiber formation, were formed earlier in Cx45.6 overexpressed cultures; however, the rate of lens cell proliferation was not affected [1].
• The nucleotide sequence in this open reading frame shows extensive sequence similarity to mouse connexin50 (Cx50), chicken Cx45.6, sheep Cx49, and human Cx50 [5].
• A novel technique combining filipin cytochemistry with freeze-fracture replica immunogold labeling (FRIL) was used to label Cx45.6 and Cx56 antibodies in cholesterol-containing gap junctions [6].

Anatomical context of GJA8

• In the present study, we used the negatively charged dye, Lucifer Yellow (LY), to examine and compare quantitative differences in dye transfer between pairs of HeLa cells stably transfected with Cx45.6 or Cx43 [7].
• Another difference was that macroscopic Cx45.6 currents were much smaller in size than the hemichannel currents induced by oocytes with similar amounts of cRNA for Cx56 [8].

Associations of GJA8 with chemical compounds

• Dual immunofluorescence and confocal microscopy of sagittal and coronal sections of the lens tissues showed that MIP(AQP0) consistently localized with gap junction plaques formed by Cx45.6 and Cx56 during the early stages of embryonic chick lens development [9].

Other interactions of GJA8

• Replacement of the N-terminus of Cx45.6 with the corresponding domain of Cx43 increased LY permeability, reduced the transjunctional voltage (V(j)) gating sensitivity, and reduced the unitary conductance of Cx45.6-43N gap junctional channels [7].
• The expression of the lens differentiation marker proteins, major intrinsic protein (MIP) and delta-crystallin, was also increased in Cx45.6-overexpressing cells [1].

Analytical, diagnostic and therapeutic context of GJA8

• Molecular cloning and functional characterization of chick lens fiber connexin 45.6 [10].
• Immunoprecipitation combined with immunoblotting analyses revealed that MIP(AQP0) was associated with Cx45.6 and Cx56 at these developmental stages [9].

References