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Genetic Manipulation of the Plant Pathogen Ustilago maydis to Study Fungal Biology and Plant Microbe Interactions
11:42

Genetic Manipulation of the Plant Pathogen Ustilago maydis to Study Fungal Biology and Plant Microbe Interactions

Published on: September 30, 2016

KP4 fungal toxin inhibits growth in Ustilago maydis by blocking calcium uptake

M J Gage1, J Bruenn, M Fischer

  • 1Donald Danforth Plant Science Center, 7425 Forsyth Boulevard, Box 1098, St Louis, MO 63105, USA.

Molecular Microbiology
|September 5, 2001
PubMed

Insights

The fungal toxin KP4 reversibly inhibits fungal cell division by blocking calcium channels and calcium-regulated signaling pathways, rather than killing cells. This effect is reversed by calcium or cAMP.

Area of Science:

  • Mycology
  • Molecular Biology
  • Biochemistry

Background:

  • KP4 is a fungal toxin from Ustilago maydis.
  • Previous studies suggested KP4 inhibits calcium channels but did not clarify its mechanism.
  • KP4's action on fungal cells was not fully understood.

Purpose of the Study:

  • To elucidate the mechanism of action of the fungal toxin KP4.
  • To investigate KP4's effect on fungal cell division and membrane interactions.
  • To determine if KP4 interferes with calcium signaling pathways.

Main Methods:

  • Investigated KP4's effect on Ustilago maydis cell division and membrane.
  • Utilized EGTA, calcium concentrations, and ionic strength buffers to test KP4's action.
  • Assessed (45)Ca uptake and the effects of cAMP and its analogue on KP4 activity.

Main Results:

  • KP4 reversibly inhibits fungal cell division without causing cell death.
  • KP4's effects are mimicked by EGTA and reversed by specific calcium concentrations or high ionic strength.
  • KP4 affects (45)Ca uptake and its inhibitory effects are abrogated by cAMP.

Conclusions:

  • KP4 likely inhibits fungal growth and division by blocking calcium-regulated signal transduction pathways.
  • The toxin's action involves reversible membrane interaction and interference with calcium homeostasis.
  • KP4 represents a potential tool for studying calcium signaling in fungi.

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