RMDN3 Antibody
Description
Overview of RMDN3 Antibody
RMDN3 antibodies are immunological reagents designed to detect and analyze the RMDN3 protein (UniProt ID: Q96TC7), which regulates endoplasmic reticulum (ER)-mitochondria contacts (MERCs), lipid radical transfer, and apoptosis. These antibodies are widely used in techniques such as Western blotting (WB), immunoprecipitation (IP), and immunofluorescence (IF) to study RMDN3's interactions, localization, and expression levels in diverse cellular contexts .
Role in ER-Mitochondria Contact Dynamics
RMDN3 antibodies have been pivotal in elucidating how mitochondrial ROS (mtROS) upregulate MERCs via RMDN3-VAPB tethering. Key findings include:
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Phosphorylation-Dependent Binding: mtROS induce phosphorylation of RMDN3 at threonine 160 (T160), enhancing its interaction with VAPB to form MERCs. Knockdown experiments using siRNA (validated by RMDN3 antibodies) showed that disrupting this interaction increases mitochondrial lipid radical accumulation and cell death .
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Lipid Radical Transfer: The TPR domain of RMDN3 facilitates lipid radical transfer from mitochondria to the ER, as demonstrated by LipiRADICAL assays and liposome experiments .
Cancer Biology Insights
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Prostate and Keratinocyte Carcinomas: RMDN3 antibodies have detected overexpression in prostate cancer (PCa) and keratinocyte carcinomas, linked to CpG island hypomethylation and MAPK pathway dysregulation .
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Therapeutic Target Potential: In acute myeloid leukemia, RMDN3 interacts with PTP1B to modulate apoptosis, highlighting its role as a biomarker or drug target .
Apoptosis Regulation
RMDN3 antibodies reveal its dual role in apoptosis:
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Pro-Survival: Under mitochondrial damage, RMDN3-VAPB tethering prevents ferroptosis by transferring lipid radicals to the ER .
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Pro-Apoptotic: Overexpression in keratinocytes induces apoptosis, suggesting context-dependent functions .
Mitochondrial Disease Links
In MELAS syndrome (mitochondrial encephalopathy), fibroblasts with high mtROS show stronger RMDN3-VAPB binding, implicating MERCs in mitochondrial disease pathology .
Limitations and Future Directions
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Kinase Identification: The kinase responsible for RMDN3 T160 phosphorylation remains unidentified. Antibody-based phosphoproteomics could resolve this .
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Mechanistic Specificity: While RMDN3 transfers lipid radicals, its selectivity for oxidized lipids versus phosphatidic acid requires further study .
Product Specs
Target Background
- Research indicates that the VAPB-PTPIP51 tethers regulate autophagy. Overexpression of VAPB or PTPIP51 tightens endoplasmic reticulum-mitochondria contacts, impairing autophagosome formation. Conversely, small interfering RNA-mediated loss of VAPB or PTPIP51 loosens contacts, stimulating autophagosome formation. PMID: 28132811
- Recent findings provide insights into the function, regulation, and protein complex formation of PTPIP51, including its involvement in signaling pathways and subcellular compartments. PMID: 27734150
- High PTPIP51 expression is correlated with glioblastoma. PMID: 25862004
- PTPIP51 is regulated by its phosphorylation status, which triggers its subcellular redistribution. PMID: 24501773
- In vivo studies demonstrate a tyrosine phosphorylation-dependent interaction of PTPIP51 with 14-3-3beta and Raf-1. Additionally, PTPIP51 exhibits a tyrosine-dependent interaction profile with DAGKalpha and PKA. PMID: 22544307
- In glioblastoma, PTPIP51 expression increases with the grade of malignancy, and PTPIP51 interacts with 14-3-3ss and PTP1B. PMID: 21972092
- PTPIP51 is phosphorylated by Lyn and c-Src kinases, and this phosphorylation is not reversed by PTP1B in acute myeloid leukemia. PMID: 21513978
- PTPIP51 expression is limited to myeloid precursor cells undergoing differentiation. In blood cells, PTPIP51 expression is restricted to differentiating and mature neutrophil granulocytes. PMID: 20627780
- PTPIP51 may be involved in the regulation of cellular processes related to differentiation, movement, or cytoskeletal organization. PMID: 15609043
- PTPIP51 is a mitochondrial protein with apoptosis-inducing function. Its N-terminal transmembrane domain is required for both mitochondrial targeting and apoptotic functions. PMID: 16820967
- PTPIP51 and PTP1B play roles in the differentiation and apoptosis of the cytotrophoblast and syncytiotrophoblast, respectively. Additionally, PTPIP51 may function as a signaling partner in angiogenesis and vascular remodeling. PMID: 18854601
- FAM82A2 is expressed in keratinocyte carcinoma and its surrounding stroma. PMID: 19012732
- Evidence strongly suggests a correlation between PTPIP51 expression and differentiation in human muscle cells. PMID: 19124842
- The methylation status of the PTPIP51 promoter appears to influence its expression, which is elevated in prostate carcinoma. PMID: 19691131
