# Divergent roles of Slingshot-1 in tauopathy

> **NIH VA I01** · LOUIS STOKES CLEVELAND VA MEDICAL CENTER · 2024 · —

## Abstract

Accumulation of toxic proteins (i.e. Aβ42 & tau) and dysfunctional mitochondria are associated with synaptic and neuronal loss in multiple neurodegenerative disorders, including Alzheimer’s disease (AD). Such clearance defects are thought to arise in large part from deficits in the autophagy-lysosome system. While mounting experimental evidence supports the notion that AD is a tauopathy at least in part driven Aβ, there is still a considerable knowledge gap in the way Aβ and tau pathogenesis are mechanistically connected. Our recently published and preliminary studies indicate that the Slingshot homolog-1 (SSH1) pathway constitutes a critical link between Aβ and tau pathogenesis. SSH1 is a protein phosphatase, classically known for its cofilin dephosphorylating activity. SSH1 is activated by oxidative stress (i.e. H2O2, Aβ, etc.) and/or intracellular Ca2+ elevation, which results in activation / dephosphorylation of cofilin. Activated cofilin can then sever F-actin (at the synapse) and/or translocate to mitochondria to promote mitochondria-mediated apoptosis. Likewise, we have found that activation of SSH1 and cofilin are required for Aβ42-induced mitochondrial dysfunction, synaptic loss, as wells as deficits in LTP and/or learning/memory in cellular and mouse models of A pathogenesis (APP/PS1). In support of these experimental findings, activated cofilin and SSH1/cofilin complexes are increased in APP/PS1 mouse brains as wells as in mitochondria of AD brains. In preliminary studies, we found that in addition to cofilin, SSH1 contains a modular and independent activity on the autophagy cargo receptor p62, which functions to regulate autophagy and tau clearance. By utilizing molecular, biochemical, cell biological, viral, and histochemical tools, we propose to (1) dissect the modular activity of SSH1 in p62-mediated autophagy and mitophagy; and (2) determine the role of SSH1 in p62-mediated autophagy and tauopathy in vivo.

## Key facts

- **NIH application ID:** 10725152
- **Project number:** 5I01BX004680-05
- **Recipient organization:** LOUIS STOKES CLEVELAND VA MEDICAL CENTER
- **Principal Investigator:** David E Kang
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2020-10-01 → 2024-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10725152

## Citation

> US National Institutes of Health, RePORTER application 10725152, Divergent roles of Slingshot-1 in tauopathy (5I01BX004680-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10725152. Licensed CC0.

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