Saturday, 18 May 2013

Metallothioneins and fungal pathogens


Metallothioneins, proteins able to capture metal ions, play a major role in the virulence of Cryptococcus neoformans, a fungal pathogen which causes severe infections in immunodeficient and immunocompetent individuals (AIDS patients, transplant receivers, and so on) This is one of the main conclusions of the research published on the journal Cell, Host & Microbe.

Metallothioneins (MT) are low molecular weight, cysteine-rich proteins. They can bind metal ions and act as chelating agents -- compounds which capture metals -- to capture and distribute biologically interesting metals (copper, zinc, cadmium, quicksilver, etc.). MTs are very heterogeneous and polymorphic, and can be found in any type of organism (prokaryotes, fungi, plants, vertebrates, etc.), in which they facilitate metal detoxification processes and help to modulate the of the organism's physiological response against a lack or excess of metals.

The new research, carried out with mice, shows that when MTs have been modified and are not able to bind metals, the pathogen is unable to infect host cells.

Refer to the following paper for more details:

Chen Ding, Richard A. Festa, Ying-Lien Chen, Anna Espart, Òscar Palacios, Jordi Espín, Mercè Capdevila, Sílvia Atrian, Joseph Heitman, Dennis J. Thiele. Cryptococcus neoformans Copper Detoxification Machinery Is Critical for Fungal Virulence. Cell Host & Microbe, 2013

Posted by Tim Sandle