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Ectopic Tyrosinase Perturbs Cellular Iron Homeostasis
Hyoseok Kim1, Kosuke Nishio1, Masahiro Abo1
1Institute for Chemical Research (ICR), Kyoto University, Uji, Kyoto 611-0011, Japan.
ACS Chemical Biology
|May 18, 2026
Summary
Ectopic tyrosinase expression causes cellular iron depletion by sequestering iron into melanin. This activates iron homeostasis pathways, impacting cell metabolism outside its natural organelle.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Biology
Background:
- Tyrosinase catalyzes melanin production within melanosomes.
- Ectopic tyrosinase expression is used in cell engineering and protein labeling.
- The impact of ectopic tyrosinase on cellular iron is not well understood.
Purpose of the Study:
- To investigate the effects of ectopic tyrosinase expression on cellular iron metabolism.
- To elucidate the mechanisms underlying tyrosinase-induced iron dysregulation.
Main Methods:
- Proteomics analysis
- Biochemical assays
- Cellular iron level measurements
Main Results:
- Ectopic tyrosinase expression leads to significant intracellular iron depletion.
- This depletion activates iron homeostasis pathways, including IRP2 signaling and ferritinophagy.
- Melanin produced by ectopic tyrosinase strongly chelates intracellular iron.
Conclusions:
- Ectopic tyrosinase expression unintentionally disrupts cellular iron homeostasis.
- Melanin's metal-chelating properties are responsible for iron sequestration.
- Iron metabolism must be considered when using tyrosinase outside its native melanosomal environment.
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