Characterization of VP2145, a Putative Histone Deacetylase T3SS Effector from Vibrio parahaemolyticus
J. FERNANDEZ (1), P. Li (1), K. Orth (1) (1) UT Southwestern Medical Center, U.S.A.

Vibrio parahaemolyticus is a Gram-negative, marine bacterium that causes acute gastroenteritis through the consumption of contaminated seafood and is also associated with wound infections and septicemia. Moreover, V. parahaemolyticus has been implicated in the reduction of the Southeast Asian shrimp production. To be a successful pathogen, this bacterium delivers effector proteins directly into the eukaryotic host cytosol through type III secretion systems (T3SS). These effector proteins hijack the host cellular machinery to create a suitable niche for bacterial survival and proliferation. The V. parahaemolyticus genome encodes two T3SSs. T3SS1 is found in all isolated strains of V. parahaemolyticus and is cytotoxic. T3SS1 orchestrates a regulated cell death by inhibiting autophagic flux, causing membrane blebbing, cell rounding, and cell lysis. Recently, we identified VP2145 as a new V. parahaemolyticus T3SS1 effector. Bioinformatic analyses revealed that VP2145 (302 a.a.) contains a class IV histone deacetylase (HDAC) domain. HDACs deacetylate lysine residues on histones, which condenses DNA structure and represses transcription. HDACs can also deacetylate, and thereby regulate, the activity of non-histone proteins. In this work, we set out to determine whether VP2145 is a T3SS1 effector and characterize its catalytic activity. To this end, we confirmed that VP2145 is secreted by T3SS1. Furthermore, we demonstrated that transfected VP2145 localizes to PML nuclear bodies in host cells. Using yeast genetics, cell biology and biochemistry, we will focus on identifying physiologically relevant proteins that interact with VP2145 in eukaryotic cells to better understand the function of VP2145 during infection.

Abstract Number: P9-254
Session Type: Poster