Prion Protectors

Editor’s choice in immunology

By | January 1, 2012

image: Prion Protectors Mav proteinsDr. Fajian Hou, Hui Zheng, Qiu-Xing Jiang, and Zhijian J. Chen, University of Texas, Southwestern

Mav proteinsDR. FAJIAN HOU, HUI ZHENG, QIU-XING JIANG, AND ZHIJIAN J. CHEN, UNIVERSITY OF TEXAS.

The paper

F. Hou et al., “MAVS forms functional prion-like aggregates to activate and propagate antiviral innate immune response,” Cell, 146:448-61, 2011.

The finding

In trying to tease apart the signaling pathway that activates an innate immune response, Zhijian “James” Chen and colleagues at the University of Texas Southwestern Medical Center discovered that an intermediary mitochondrial protein called MAVS acts like a prion—activating other MAVSs and aggregating—and in this form potently initiates the next signal in the cascade that leads to innate cytokine production. This finding is the first report of a prion-like protein in mammalian cells.

The receptor

A cell infected with an RNA virus such as influenza alerts other cells by activating innate immune pathways. A cytoplasmic receptor, RIG-1, detects viral RNA particles and activates the mitochondrial membrane protein MAVS, which in turn activates the next step in the signaling cascade. Chen and colleagues showed that once RIG-1 had turned on the MAVS proteins, those MAVSs could activate other MAVSs in vitro, even when RIG-1 was absent. “They form the seed that cause the other MAVS to aggregate,” says Chen.

The amplifier

Chen thinks that the prion-like activation and aggregation of MAVS proteins can amplify the signal from just a few molecules of activated RIG-1. By multiplying the next step, the activated MAVS convey a stronger downstream signal.

The implication

With such a simple way to amplify a signal, “one wonders how common this is in signal transduction,” says The Scripps Research Institute’s Bruce Beutler, as many signal transduction pathways could benefit from such an amplifying step.

 

Advertisement

Add a Comment

Avatar of: You

You

Processing...
Processing...

Sign In with your LabX Media Group Passport to leave a comment

Not a member? Register Now!

LabX Media Group Passport Logo

Comments

Avatar of: Robert Miles

Robert Miles

Posts: 1

January 14, 2012

So there's been no mention of the prion that the human brain uses as it's natural defense against Alzheimer's?  I've found nothing on whether that one appears within brain cells, or only outside the cells, though.  Apparantly, no other species uses this method.

Avatar of:

Posts: 0

January 14, 2012

So there's been no mention of the prion that the human brain uses as it's natural defense against Alzheimer's?  I've found nothing on whether that one appears within brain cells, or only outside the cells, though.  Apparantly, no other species uses this method.

Avatar of:

Posts: 0

January 14, 2012

So there's been no mention of the prion that the human brain uses as it's natural defense against Alzheimer's?  I've found nothing on whether that one appears within brain cells, or only outside the cells, though.  Apparantly, no other species uses this method.

Advertisement
EMD Millipore
EMD Millipore

Popular Now

  1. The Mycobiome
    Features The Mycobiome

    The largely overlooked resident fungal community plays a critical role in human health and disease.

  2. Antibody Alternatives
    Features Antibody Alternatives

    Nucleic acid aptamers and protein scaffolds could change the way researchers study biological processes and treat disease.

  3. Holding Their Ground
    Features Holding Their Ground

    To protect the global food supply, scientists want to understand—and enhance—plants’ natural resistance to pathogens.

  4. Circadian Clock and Aging
    Daily News Circadian Clock and Aging

    Whether a critical circadian clock gene is deleted before or after birth impacts the observed aging-related effects in mice.

Advertisement
Bio-Rad
Bio-Rad
Advertisement
Life Technologies