A pathogen effector co-opts a host RabGAP protein to remodel pathogen interface and subvert defense-related...

Area of Science:

• Plant pathology
• Molecular plant-microbe interactions
• Cellular microbiology

Background:

• Pathogens evolve mechanisms to manipulate host cell membrane dynamics for survival against immune responses.
• Host-pathogen interfaces are critical sites where pathogens remodel host cell membranes to facilitate infection.

Purpose of the Study:

• To understand how pathogens transform host-pathogen interfaces to their advantage.
• To identify pathogen effectors involved in manipulating host membrane dynamics and immune responses.

Main Methods:

• Identification of a conserved effector (PiE354) secreted by plant pathogenic oomycetes.
• Investigation of the interaction between PiE354 and the host Rab GTPase-activating protein (RabGAP), TOPGAP.
• Analysis of the role of TOPGAP in regulating Rab8a GTPase activity at the plasma membrane.

Main Results:

• The oomycete effector PiE354 hijacks the host TOPGAP protein, a susceptibility factor.
• PiE354 utilizes TOPGAP's GTPase-activating protein (GAP) activity to remove Rab8a from the plasma membrane.
• This action diverts Rab8a-mediated immune trafficking away from the host-pathogen interface, suppressing host defenses.

Conclusions:

• Pathogens have evolved sophisticated effectors that co-opt host regulatory components to subvert immune responses.
• The PiE354 effector's mechanism provides mechanistic insights into how pathogens reprogram host membrane dynamics.
• This study highlights a novel strategy employed by oomycetes to evade host immunity by manipulating host secretion pathways.