Open AccessToxoplasma gondii Clp family protein: TgClpB1 plays a crucial role in thermotolerance
Author(s) -
Shinuo Cao,
Nali Du,
Heming Chen,
Yu Pang,
Zhaoxia Zhang,
Jun Zheng,
Honglin Jia
Publication year - 2017
Publication title -
oncotarget
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.373
H-Index - 127
ISSN - 1949-2553
DOI - 10.18632/oncotarget.20989
Subject(s) - toxoplasma gondii , medicine , biology , immunology , genetics , computational biology , bioinformatics , antibody
Caseinolytic peptidase B (ClpB) plays a pivotal role in suppressing and reversing protein aggregation. Toxoplasma gondii is an intracellular parasitic protozoan that infects a wide variety of mammals and birds and therefore is exposed to a broad range of living condition. We screened ToxoDB (http://ToxoDB.org) and identified 10 putative T. gondii genes encoding members of the Clp superfamily of caseinolytic proteases and chaperones. Of these, we focused on characterizing the Class I ATP-dependent molecular chaperones Tg ClpB1, Tg ClpB2, and Tg ClpB3. We found that Tg ClpB1, the most divergent of the five T. gondii Class I Clp ATPases, is cytoplasmic, Tg ClpB2 is found in the mitochondria of the parasites, and Tg ClpB3 is a ClpB with novel apicoplast localization. Knockout strains of Tg ClpB1 and Tg ClpB2 were established by CRISPR/Cas9 mutagenesis, and their complementing strains were constructed with FLAG-tag. Although knockout of Tg ClpB1 or Tg ClpB2 did not affect growth under normal circumstances, Tg ClpB1 was required for T. gondii thermotolerance. The growth, replication, and invasion capabilities of Tg ClpB1-deficient mutants were significantly inhibited after extracellular parasites were pretreated at 45°C. Moreover, Tg ClpB1 were observed at the poles of the Δ Tg ClpB1 FLAG-tagged strain treated at 42°C.