Background: Acanthamoeba spp. can cause serious human infections, including Acanthamoeba keratitis, granulomatous amoebic encephalitis and cutaneous acanthamoebiasis. Cysteine biosynthesis and the L-serine metabolic pathway play important roles in the energy metabolism of Acanthamoeba spp. However, no study has confirmed the functions of cysteine synthase (AcCS) in the cysteine pathway and phosphoglycerate dehydrogenase (AcGDH) or phosphoserine aminotransferase (AcSPAT) in the non-phosphorylation serine metabolic pathway of Acanthamoeba.
Methods: The AcCS, AcGDH and AcSPAT genes were amplified by PCR, and their recombinant proteins were expressed in Escherichia coli. Polyclonal antibodies against the recombinant proteins were prepared in mice and used to determine the subcellular localisation of each native protein by confocal laser scanning microscopy. The enzymatic activity of each recombinant protein was also analysed. Furthermore, each gene expression level was analysed by quantitative PCR after treatment with different concentrations of cysteine or L-serine.
Results: The AcCS gene encodes a 382-amino acid protein with a predicted molecular mass of 43.1 kDa and an isoelectric point (pI) of 8.11. The AcGDH gene encodes a 350-amino acid protein with a predicted molecular mass of 39.1 kDa and a pI of 5.51. The AcSPAT gene encodes a 354-amino acid protein with a predicted molecular mass of 38.3 kDa and a pI of 6.26. Recombinant AcCS exhibited a high cysteine synthesis activity using O-acetylserine and NaS as substrates. Both GDH and SPAT catalysed degradation, rather than synthesis, of serine. Exogenous L-serine or cysteine inhibited the expression of all three enzymes in a time- and dose-dependent manner.
Conclusions: This study demonstrated that AcCS participates in cysteine biosynthesis and serine degradation via the non-phosphorylation serine metabolic pathway, providing a molecular basis for the discovery of novel anti-Acanthamoeba drugs.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6257972 | PMC |
http://dx.doi.org/10.1186/s13071-018-3188-7 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China.
Host plants and various fungicides inhibit plant pathogens by inducing the release of excessive reactive oxygen species (ROS) and causing DNA damage, either directly or indirectly leading to cell death. The mechanisms by which the oomycete manages ROS stress resulting from plant immune responses and fungicides remains unclear. This study elucidates the role of histone acetylation in ROS-induced DNA damage responses (DDR) to adapt to stress.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Hedgehog (Hh) morphogen governs embryonic development and tissue homeostasis through the Ci/Gli family transcription factors. Here we report that Hh induces phase separation of the fused (Fu)/Ulk family kinases to allosterically regulate Ci/Gli. We find that Hh-induced phosphorylation of Fu/Ulk3 promotes SUMOylation of their inverted phosphorylation-dependent SUMOylation motifs.
View Article and Find Full Text PDFCancer Chemother Pharmacol
January 2025
Department of Obstetrics and Gynecology, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China.
Purpose: Ovarian clear cell carcinoma is a highly malignant gynecological tumor characterized by a high rate of chemotherapy resistance and poor prognosis. The PI3K/AKT/mTOR pathway is well-known to be closely related to the progression of various malignancies, and recent studies have indicated that this pathway may play a critical role in the progression and worsening of OCCC.
Methods: In this study, we investigated the combined effects of WX390, a dual inhibitor of PI3K/mTOR, and cisplatin on OCCC through both in vitro and in vivo experiments to further elucidate their therapeutic effects.
Cells
December 2024
Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan.
The Hippo pathway, a kinase cascade, coordinates with many intracellular signals and mediates the regulation of the activities of various downstream transcription factors and their coactivators to maintain homeostasis. Therefore, the aberrant activation of the Hippo pathway and its associated molecules imposes significant stress on tissues and cells, leading to cancer, immune disorders, and a number of diseases. Cellular senescence, the mechanism by which cells counteract stress, prevents cells from unnecessary damage and leads to sustained cell cycle arrest.
View Article and Find Full Text PDFInt J Mol Med
March 2025
Department of Biomedical Sciences, Chung Shan Medical University, Taichung 402306, Taiwan, R.O.C.
Oral squamous cell carcinoma (OSCC) is a type of head and neck cancer (HNC) with a high recurrence rate, which has been reported to be associated with the presence of cancer stem cells (CSCs). Tribbles pseudokinase 3 (TRIB3) is involved in intracellular signaling and the aim of the present study was to investigate the role of TRIB3 in the maintenance of CSCs. Analysis of The Cancer Genome Atlas database samples demonstrated a positive correlation between TRIB3 expression levels and shorter overall survival rates in patients with HNC.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!