Intracellular micronutrient mobilisation fuels Candida albicans pathogenicity Duncan
Intracellular micronutrient mobilisation fuels Candida albicans pathogenicity Duncan Wilson MRC Centre for Medical Mycology
Why are micronutrients an issue? Nutritional immunity Host Pathogen micronutrients nutritional immunity Disease
[H+] Crawford et al. Under revision PLo. S Pathogens – Accepted, like last week! Pra 1 Zrt 2 ? (also Zrc 1 -zincosomes) Vacuole MRC Centre for Medical Mycology Citiulo et al. , PLo. S Pathogens, 2012; Wilson, Metallomics, 2015
Intracellular zinc reserves can fuel up to seven generations of growth = preculture [zinc] MRC Centre for Medical Mycology
Intracellular zinc reserves can fuel pathogenicity MRC Centre for Medical Mycology
[H+] Pra 1 Zrt 2 ? Vacuole MRC Centre for Medical Mycology
Candida albicans vacuolar zinc accumulation – yeast & hyphae 0 5 0 20 60 180 min 20 60 MRC Centre for Medical Mycology
? * Zn. T-type transporters * (Cation efflux family) * * * MRC Centre for Medical Mycology *
viz 1Δ Wt DIC MRC Centre for Medical Mycology Zin. Pyr-1 Overlay
[H+] 60 min Pra 1 Zrt 2 Zrt 1 180 min Viz 1 ? Vacuole MRC Centre for Medical Mycology
High-to-low zinc shift * * ZIP-type transporters MRC Centre for Medical Mycology
Intracellular zinc reserves can fuel pathogenicity: Zrt 3 and Zrt 4 dependent
[H+] Pra 1 Zrt 2 <180 min Viz 1 Zrt 3/4 <60 min Vacuole MRC Centre for Medical Mycology
MRC Centre for Medical Mycology
High to low zinc environment Zrt 3 MRC Centre for Medical Mycology
Colony morphology on 10% serum agar Wt zrt 3Δ Wt pde 1Δ Modern-day Aberdeen: Manchester, 2004: Probably a coincidence, but. . MRC Centre for Medical Mycology
Zrt 3 Zn 2+ to Zn 2+ Sig na ? ls Sig nal als s n g i S als n ig S et al. Ras 1 Cyr 1 Predicted PKA phosphorylation site c. AMP Pde 2 Pi Targets MRC Centre for Medical Mycology Pde 1 PKA Pi ? Zrt 3
A shift from high to low zinc triggers rapid cyclic AMP accumulation Ctrl The plasma membrane transporter (transceptor? ) Zrt 2 – required for maintenance
A shift from high to low zinc triggers rapid cyclic AMP accumulation Zn 2+ to Zn 2+ Ras 1 Cyr 1 Pde 2 c. AMP Pde 1 PKA Pi ? Zrt 3
Ø • High to low zinc transition induces vacuolar zinc efflux in Candida albicans (Wt) × • Deletion of ZRT 3, TPK 2 (PKA), CYR 1 (adenylate cyclase), RAS 1, or ZRT 2 prevents vacuolar zinc efflux ? Zrt 2 × Ras 1 Cyr 1 c. AMP • Chemical inhibition of adenylate cyclase or PKA activity prevents vacuolar zinc efflux Pi ? • Deletion of PDE 1 or treatment with PDEase inhibitors enhances vacuolar zinc efflux Zrt 3 Vacuole × PKA × Pde 1 ×
Ø Current working model: • Cells perceive a drop in environmental zinc via plasma membrane Zrt 2 ? Ras 1 Cyr 1 • The signal is transduced via the Ras 1/c. AMP/PKA pathway… c. AMP • …resulting in Zrt 3 phosphorylation and vacuolar zinc export Pi ? Zrt 3 Vacuole PKA Pde 1
Full cycal
Thanks The zinc team: • Dhara Malavia • Aaron Crawford* • Me • Omran Alamir* • Laura Lehtovirta • (Mohammad Alsarraf) Core Facilities
Summary [H+] Pra 1 Zrt 2 Ras 1 Cyr 1 c. AMP Viz 1 Zrt 3 Vacuole MRC Centre for Medical Mycology Pi ? PKA Pde 1
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