Sinha D, et al. (2010) Role of Magmas in protein transport and human mitochondria biogenesis. Hum Mol Genet 19(7):1248-62
Abstract: Magmas, a conserved mammalian protein essential for eukaryotic development, is overexpressed in prostate carcinomas and cells exposed to granulocyte-macrophage colony-stimulating factor (GM-CSF). Reduced Magmas expression resulted in decreased proliferative rates in cultured cells. However, the cellular function of Magmas is still elusive. In this report we have showed that human Magmas is an ortholog of S. cerevisiae having similar functions and is critical for protein translocation across mitochondrial inner membrane. Human Magmas shows a complete growth complementation of Deltapam16 yeast cells at all temperatures. Based on our analysis we report that Magmas localizes into mitochondria and is peripherally associated with inner mitochondrial membrane in yeast and humans. Magmas forms a stable subcomplex with J-protein Pam18 or DnaJC19 through its C-terminal region and is tethered to TIM23 complex of yeast and humans. Importantly, amino acid alterations in Magmas leads to reduced stability of the subcomplex with Pam18 that results in temperature sensitivity and in vivo protein translocation defects in yeast cells. These observations highlight the central role of Magmas in protein import and mitochondria biogenesis. In humans absence of a functional DnaJC19 leads to dilated cardiac myophathic syndrome (DCM), a genetic disorder with characteristic features of cardiac myophathy and neurodegeneration. We propose that the mutations resulting in decreased stability of functional Magmas:DnaJC19 subcomplex at human TIM23 channel leads to impaired protein import and cellular respiration in DCM patients. Together, we propose a model showing how Magmas:DnaJC19 subcomplex is associated with TIM23 complex and thus regulates mitochondrial import process.
|Status: Published||Type: Journal Article||PubMed ID: 20053669|
Topics addressed in this paper
Number of different genes curated to this paper: 8
- To go to the Locus page for a gene, click on the gene name.
|Fungal Related Genes/Proteins|
|Non-Fungal Related Genes/Proteins|
|Protein Physical Properties|
|Protein Sequence Features|
|Protein/Nucleic Acid Structure|