Disease relevance of Gjb3

• For functional promoter analysis, the rat choriocarcinoma cell line Rcho-1 and the mouse keratinocyte cell line Hel37, which both express Cx31, were chosen [1].

High impact information on Gjb3

• Molecular cloning and characterization of a new member of the gap junction gene family, connexin-31 [2].
• When conservation of predicted phosphorylation sites is used to adjust the alignment of Cx31 to other connexins, a unique alignment of three predicted protein kinase C phosphorylation sites near the carboxyl terminus of Cx31 with three sites at the carboxyl terminus of Cx43 is revealed [2].
• In contrast, expression of Gjb3 in embryonic stem cells depended on the basal promoter together with the intron [3].
• Thus, expression of Gjb3 in keratinocytes and embryonic stem cells is regulated by different cis-regulatory elements and differs in its requirements for the intron in situ [3].
• Connexin31 (Cx31) is encoded by the gene Gjb3 and expressed throughout mouse development n a complex pattern; in adult mice it becomes restricted to the granular layer of epidermis, testis, and placenta [3].

Biological context of Gjb3

• Like most connexin genes, Gjb3 is composed of two exons, the second of which contains the whole coding region and is separated from the first exon by an intron of 2.3 kb [3].
• Here we have analyzed the structure of mouse Gjb3 as well as its transcriptional regulation by transient transfection of reporter gene constructs in HM1 mouse embryonic stem cells and a mouse keratinocytederived cell line, Hel37, as model systems for early development and skin, respectively [3].
• Thus, Cx31 may play a role in cell-cell communication during spermatogenesis [4].
• The first exon of the Cx31 gene is preceded by a TATA-less promoter region [1].
• The connexin31 (Cx31) gene, a member of the connexin multigene family, is expressed in a characteristic spatiotemporal pattern during placental development in rodents [1].

Anatomical context of Gjb3

• Immunohistochemical analysis with mouse anti-Cx31 antibody gave a similar staining pattern, providing further evidence that the gap-junction protein is abundant in the basal seminiferous epithelium, in accordance with the cellular distribution of Cx31 mRNA [4].
• During the postnatal spermatogenic process, the Cx31-specific signal became detectable at 15 dpp and onward by in situ hybridization, and apparently localized in the basal compartment of seminiferous epithelium where active spermatogonia and early primary spermatocytes reside [4].
• In adult testes, spermatids of elongation phase were also Cx31 positive [4].
• Unlike the pan-connexin peptide, connexin 31 and connexin 33 peptides appeared to have little effect on inducing apoptosis and germ cell loss [5].

Other interactions of Gjb3

• Differential expression of gap-junction gene connexin 31 in seminiferous epithelium of rat testes [4].
• To explore the role(s) of connexins during spermatogenesis, we utilized the small peptide antagonistic approach to specifically deplete connexin 31, connexin 33, and pan-connexin [5].

Analytical, diagnostic and therapeutic context of Gjb3

• Our findings by RT-PCR indicate that the Cx31 gene is expressed in testis tissue of adult and postnatal rats [4].

References