# Novel role of mitochondrial carrier protein PSAP in regulation of both apoptosis and autophagy in ALS > **NIH NIH R01** · UNIVERSITY OF TEXAS OF THE PERMIAN BASIN · 2024 · $457,769 ## Abstract Amyotrophic lateral sclerosis (ALS) is one of most devastating neurodegenerative disorders characterized by the degeneration of motor neurons, paralysis, and often accompanied by cognitive dementia. In addition to genetic mutations, the biggest risk factor for ALS is aging. Although dysregulation of apoptosis and mitochondrial quality control, and impaired autophagy, the fundamental physiological processes crucial for maintaining cellular homeostasis, have been identified as playing pivotal roles in the pathogenesis of ALS, the mechanisms underlying the dysregulation of these processes remain elusive. Using the superoxide dismutase 1 mutant (SOD1G93A) mouse model of ALS, our preliminary data intriguingly revealed that knockout of PSAP (presenilin-associated protein), also known as MTCH1, which was originally identified as a mitochondrial proapoptotic protein by our group, greatly improved motor function and extended the lifespan of the SOD1G93A mice. These novel findings led to this proposal to investigate the molecular mechanism whereby PSAP contributes to the pathogenesis of ALS. Furthermore, our data revealed a significant decrease in the activation of caspase-3 and the levels of p62-positive inclusion bodies in the spinal cord of SOD1G93A mice upon PSAP knockout, implying that PSAP knockout exerts a neuroprotective effect by inhibiting apoptosis and enhancing autophagic activity. Moreover, our study discovered that PSAP interacts with voltage-dependent anion channel 1 (VDAC1), a protein known to play a crucial role in regulating both apoptosis and autophagy. Additionally, our study has demonstrated that PSAP interacts with death receptor 6 (DR6), which has been implicated in transducing the pathogenic effect of toxic factors secreted by astrocytes expressing SOD1G93A. These novel findings lead to this proposal to elucidate the molecular mechanism by which PSAP contributes to the pathogenesis of ALS. We hypothesize that PSAP functions as a key molecule to bridge cell surface receptor DR6 and mitochondrial VDAC1, establishing a distinctive mitochondrial pathway to mediate the toxic effects of factors released by neighboring cells, such as astrocytes expressing SOD1G93A, leading to neurodegeneration by dysregulating both apoptosis and autophagy. Using our novel global and motoneuron-specific PSAP- knockout mouse models, the proposed study will investigate the pathological role of PSAP in ALS, specifically, focusing on disease-related apoptosis and autophagy in vivo. Moreover, using our newly established novel PSAP-knockout cell line in motoneuron-like NSC34 cells, we will further elucidate the novel molecular mechanism underlying the regulatory role of PSAP in apoptosis, autophagy, and mitochondrial quality control under relevant stress conditions in vitro. The success of the proposed study will yield novel insights into the molecular mechanism underlying the pathogenesis of ALS and lead to the identification of new therapeutic targets for devel... ## Key facts - **NIH application ID:** 10981464 - **Project number:** 1R01NS134931-01A1 - **Recipient organization:** UNIVERSITY OF TEXAS OF THE PERMIAN BASIN - **Principal Investigator:** XUEMIN XU - **Activity code:** R01 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $457,769 - **Award type:** 1 - **Project period:** 2024-07-01 → 2029-05-31 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10981464 ## Citation > US National Institutes of Health, RePORTER application 10981464, Novel role of mitochondrial carrier protein PSAP in regulation of both apoptosis and autophagy in ALS (1R01NS134931-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10981464. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*