Molecular Mechanism for the Thermo-Sensitive Phenotype of CHO-MT58 Cell Line Harbouring a Mutant CTP:Phosphocholine Cytidylyltransferase.

Bibliographic Details
Title: Molecular Mechanism for the Thermo-Sensitive Phenotype of CHO-MT58 Cell Line Harbouring a Mutant CTP:Phosphocholine Cytidylyltransferase.
Authors: Lívia Marton, Gergely N Nagy, Olivér Ozohanics, Anikó Lábas, Balázs Krámos, Julianna Oláh, Károly Vékey, Beáta G Vértessy
Source: PLoS ONE, Vol 10, Iss 6, p e0129632 (2015)
Publisher Information: Public Library of Science (PLoS), 2015.
Publication Year: 2015
Collection: LCC:Medicine
LCC:Science
Subject Terms: Medicine, Science
More Details: Control and elimination of malaria still represents a major public health challenge. Emerging parasite resistance to current therapies urges development of antimalarials with novel mechanism of action. Phospholipid biosynthesis of the Plasmodium parasite has been validated as promising candidate antimalarial target. The most prevalent de novo pathway for synthesis of phosphatidylcholine is the Kennedy pathway. Its regulatory and often also rate limiting step is catalyzed by CTP:phosphocholine cytidylyltransferase (CCT). The CHO-MT58 cell line expresses a mutant variant of CCT, and displays a thermo-sensitive phenotype. At non-permissive temperature (40°C), the endogenous CCT activity decreases dramatically, blocking membrane synthesis and ultimately leading to apoptosis. In the present study we investigated the impact of the analogous mutation in a catalytic domain construct of Plasmodium falciparum CCT in order to explore the underlying molecular mechanism that explains this phenotype. We used temperature dependent enzyme activity measurements and modeling to investigate the functionality of the mutant enzyme. Furthermore, MS measurements were performed to determine the oligomerization state of the protein, and MD simulations to assess the inter-subunit interactions in the dimer. Our results demonstrate that the R681H mutation does not directly influence enzyme catalytic activity. Instead, it provokes increased heat-sensitivity by destabilizing the CCT dimer. This can possibly explain the significance of the PfCCT pseudoheterodimer organization in ensuring proper enzymatic function. This also provide an explanation for the observed thermo-sensitive phenotype of CHO-MT58 cell line.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1932-6203
Relation: http://europepmc.org/articles/PMC4470507?pdf=render; https://doaj.org/toc/1932-6203
DOI: 10.1371/journal.pone.0129632
Access URL: https://doaj.org/article/cfe84253e72e440abf15cfd9a279ed69
Accession Number: edsdoj.fe84253e72e440abf15cfd9a279ed69
Database: Directory of Open Access Journals
More Details
ISSN:19326203
DOI:10.1371/journal.pone.0129632
Published in:PLoS ONE
Language:English