# Control of Mitochondrial Function by SPFH Proteins in Pathogenic Yeast

> **NIH NIH SC3** · JOHN JAY COLLEGE OF CRIMINAL JUSTICE · 2021 · $119,098

## Abstract

The mitochondrion is the major energy-producing organelle of the cell and coordinates key activities such
as signaling, apoptosis, and phospholipid synthesis. These processes are essential for survival and
pathogenesis of Candida albicans, the most common fungal pathogen in humans. C. albicans respiration
occurs via three distinct pathways compared to vertebrates and is associated with virulence properties such
as morphogenesis and cell wall synthesis. Our long-term research goal is to understand the cellular and
molecular mechanisms that govern C. albicans survival in response to environmental stress and antifungal
drugs. We previously discovered that gene classes involved mitochondrial functions are highly transcribed
in response to osmotic and cell wall stress, and the gene SLP3 (stomatin like protein 3) was significantly
upregulated. SLP3 is a member of the conserved SPFH (Stomatin, Prohibitin, Flotillin, HflK/HflC) protein
superfamily. In eukaryotes, SPFH proteins are required for essential mitochondrial processes such as
respiration, mitophagy, and apoptosis and mediate pathogenicity in several parasites. Our objective in this
proposal is to determine the role of the C. albicans SPFH protein family in mitochondrial function. We were
the first to demonstrate that Slp3p overproduction disrupted mitochondrial membrane potential and
triggered apoptotic-like death specifically following prolonged exposure to oxidative stress. However, the
molecular function Slp3p remains unknown. Thus, our central hypothesis is that C. albicans SPFH proteins
form membrane complexes to coordinate mitochondrial function. This hypothesis is based upon
observations with mammalian SPFH proteins and our published and preliminary findings. Human SPFH
complexes appear as punctate foci when viewed using fluorescence microscopy. We found that Slp3p form
puncta at the plasma membrane. Further, we identified a mitochondrial targeting signal in Slp2p, Phb1p and
Phb2p, and our Slp2p-GFP fusion protein formed mitochondrial puncta. We will utilize a high-throughput
molecular genetic and cellular approach that is cost-effective and time-saving to determine SPFH protein
localization, protein complex composition, cellular function, and role in C. albicans infection. We will create
SPFH-GFP fusion proteins and use fluorescence microscopy to determine cellular localization. We will
construct SPFH-epitope-tagged strains and perform Co-IP and LC-MS/MS analyses to identify putative
SPFH protein binding partners. We will create SPFH mutants via CRISPR-Cas9 genome editing and
phenotypically characterize mutant strains in growth and cellular assays. We will examine SPFH function in
C. albicans pathogenesis using a novel invertebrate infection system. Our findings will address a poorly
understood area in C. albicans biology and provide a model for studying SPFH proteins in pathogenic fungi.
This proposal is innovative as we will characterize the SPFH family in the context of a critical, ye...

## Key facts

- **NIH application ID:** 10332017
- **Project number:** 1SC3GM135016-01A1
- **Recipient organization:** JOHN JAY COLLEGE OF CRIMINAL JUSTICE
- **Principal Investigator:** Jason Malcolm Rauceo
- **Activity code:** SC3 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $119,098
- **Award type:** 1
- **Project period:** 2021-09-16 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10332017

## Citation

> US National Institutes of Health, RePORTER application 10332017, Control of Mitochondrial Function by SPFH Proteins in Pathogenic Yeast (1SC3GM135016-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10332017. Licensed CC0.

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