| Background and Objectives:Connexins, or gap junction proteins, are a family of structurally related trans-membrane proteins that assemble to form vertebrate gap junctions. Each gap junction is composed of two hemichannels, or connexons, constructed by six connexin molecules. Gap junctions are essential for many physiological processes, such as the coordinated depolarization of cardiac muscle, proper embryonic development, and the conducted response in microvasculature. For this reason, mutations in connexin-encoding genes can lead to functional and developmental abnormalities. Gap junction beta-6protein (GJB6), also known as connexin30(Cx30) is a component of the gap junction complex. Mutation in the gap junction beta6(GJB6) gene is associated with an autosomal dominant disorder, Hidrotic Ectodermal Dysplasia (HED), characterized by congenital nail clubbing, alopecia and palmoplantar keratoderma. In this study, we have investigated the mutation in GJB6gene in a Chinese family with congenital nail clubbing and alopecia.Materials and Methods:We have selected patients from a Chinese family, who are suffering from HED, with four affected and two unaffected. All the affected patients had the similar clinical presentation. Physical examination revealed loss of scalp hair, eyelashes, eyebrows and body hair on other parts of the body. Genomic DNA was isolated from the peripheral blood of the individuals, and whole coding region of GJB6was amplified by polymerase chain reaction (PCR). The PCR products were analyzed by direct sequencing. Results:Sequencing identified a heterozygous missense mutation31Gâ†'A in the GJB6gene leading the predicted amino acid change glyll-to-arg (G11R) in the cytoplasmic amino-terminus of GJB6protein of affected individuals but not in normal healthy control. Although the effect of the mutations is not fully understood, this probably causes abnormal transport activity through the gap junctions.Conclusions:This investigation identifies a Gâ†'A missense mutation in GJB6gene (G11R in GJB6protein), responsible for the congenital disorder characterized with HED in a Chinese family. Background and Objectives:Adenosine monophosphate deaminase (AMPD), also known as myoadenylate deaminase, is a complex allosteric enzyme in higher eukaryotes. AMPD1, also known as myoadenylate deaminase, is the muscle-specific form of AMPD. AMPD1catalyzes the deamination of adenosine monophosphate (AMP) to inosine monophosphate (IMP) plus ammonia (NH3) in skeletal muscle, and plays an important role in the purine nucleotide cycle. The deficiency of AMPD1in skeletal muscle causes limited capacity to form IMP, resulting in an elevation of AMP. In a previous study of our research group, the whole genome association study (WGAS) was performed to identify the risk SNP for autism, and the risk SNP was found at the locus adjacent to AMPD1, which suggests that AMPD1might be the candidate risk gene for autism. However, its biological feature is unevaluated properly. In this study, we have investigated the cellular distribution of AMPD1in somatic cell line HEK293and neuroblastoma cell line SH-SY5Y.Methods:RNA was isolated from mouse muscle and cDNA was synthesized. The AMPD1gene was amplified by PCR. The3Xflag-mAMPD1plasmid was constructed. The recombinant plasmid was transfected into HEK293and SH-SY5Y cell lines. Expression of AMPD1was studied to investigate cellular location in these two cell lines by immunohistochemistry.Results:Agarose gel electrophoresis confirmed the AMPD1and plasmids expressions, which were used to study the cellular distribution of AMPD1protein. Immunohistochemical staining showed that AMPD1is specifically localized in the cytoplasm. Conclusions:In this study, we have examined the distribution of AMPD1in somatic cell line HEK293and neuroblastoma cell line SH-SY5Y, and we report here that AMPD1is localized in the cytoplasm of investigated cells. |
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