Posts filled under #genic_mag

An extract on #genic_mag

This gene is a member of the melanoma antigen gene (MAGE) family. Most of the genes of this family encode tumor specific antigens that are not expressed in normal adult tissues except testis. Although the protein encoded by this gene shares strong homology with members of the MAGE family, it is expressed in almost all normal adult tissues. This gene has been demonstrated to be involved in the p75 neurotrophin receptor mediated programmed cell death pathway. Three transcript variants encoding two different isoforms have been found for this gene.

This gene is related to members of the MAGED gene family, in terms of the sequence similarity and the chromosome location. This gene is expressed only in brain and ovary among normal tissues, and two transcript variants of this gene are specifically expressed in glioma cells among cancer cells. This gene and the other MAGED genes are clustered on chromosome Xp11. Multiple alternatively spliced transcript variants have been found for this gene, however, the full length nature of some variants has not been defined.

This gene is a member of the MAGED gene family. While the MAGEA and MAGEB genes are silent in normal tissues with the exception of testis and placenta, the MAGED genes are expressed ubiquitously. The MAGED genes are clustered on chromosome Xp11. This gene is located in Xp11.2, a hot spot for X-linked mental retardation (XLMR). Multiple alternatively spliced transcript variants have been found for this gene, however, the full length nature of some variants has not been defined.

When expressed in Xenopus laevis oocytes, MagT1 mediates saturable Mg2+ uptake with a Km of 0.23 mM. Transport of Mg2+ by MagT1 is rheogenic, voltage-dependent, and does not display time-dependent inactivation. Transport is specific to Mg2+, as other divalent cations do not evoke currents. Large external concentrations of some cations inhibited Mg2+ transport (Ni2+, Zn2+, Mn2+) in MagT1-expressing oocytes although Ca2+and Fe2+ were without effect. MagT1 has an N-terminal thioredoxin domain of unknown function. Zhou and Clapham identified two mammalian genes, MagT1 and TUSC3, catalyzing Mg2+ influx. MagT1 is universally expressed in all human tissues, and its expression level is upregulated in low extracellular Mg2+. Knockdown of either MagT1 or TUSC3 protein lowered the total and free intracellular Mg2+concentrations in mammalian cell lines. Morpholino knockdown of MagT1 and TUSC3 protein expression in zebrafish embryos resulted in early developmental arrest; excess Mg2+ or supplementation with mammalian mRNAs rescued these effects. Thus, MagT1 and TUSC3 are vertebrate plasma membrane Mg2+transport system.

logo