Phosphorylation and other post-translational modifications of red blood cell (RBC) proteins govern membrane function and have a role in the invasion of RBCs by the malaria parasite, Plasmodium falciparum. Furthermore, a percentage of RBC proteins are palmitoylated, although the functional consequences are unknown. We establish dynamic palmitoylation of 118 RBC membrane proteins using click chemistry and acyl biotin exchange (ABE)-coupled LC−MS/MS and characterize their involvement in controlling membrane organization and parasite invasion. RBCs were treated with a generic palmitoylation inhibitor, 2-bromopalmitate (2-BMP), and then analyzed using ABE-coupled LC−MS/ MS. Only 42 of the 118 palmitoylated proteins detected were palmitoylated in the 2-BMP-treated sample, indicating that palmitoylation is dynamically regulated. Interestingly, membrane receptors such as semaphorin 7A, CR1, and ABCB6, which are known to be involved in merozoite interaction with RBCs and parasite invasion, were found to be dynamically palmitoylated, including the blood group antigen, Kell, whose antigenic abundance was significantly reduced following 2-BMP treatment. To investigate the involvement of Kell in merozoite invasion of RBCs, a specific antibody to its extracellular domain was used. The antibody targeting Kell inhibited merozoite invasion of RBCs by 50%, implying a role of Kell, a dynamically palmitoylated potent host-derived receptor, in parasite invasion. Furthermore, a significant reduction in merozoite contact with the RBC membrane and a consequent decrease in parasite invasion following 2-BMP treatment demonstrated that palmitoylation does indeed regulate RBC susceptibility to parasite invasion. Taken together, our findings revealed the dynamic palmitoylome of RBC membrane proteins and its role in P. falciparum invasion.
Efficient regeneration of explants devoid of intrinsic somaclonal variations is a cardinal step in plant tissue culture, thus, a vital component of transgenic technology. However, recalcitrance of economically important crops to tissue culture-based organogenesis ensues a setback in the use of transgenesis in the genetic engineering of crop plants. The present study developed an optimized, genotype-independent, nonconventional tissue culture-independent in planta strategy for the genetic transformation of flax/linseed. This apical meristem-targeted in planta transformation protocol will accelerate value addition in the dual purpose industrially important but recalcitrant fiber crop flax/linseed. The study delineated optimization of Agrobacterium tumefaciens-mediated transformation and stable T-DNA (pCambia2301:GUS:nptII) integration in flax. It established successful use of a stringent soilrite-based screening in the presence of 30 mg/L kanamycin for the identification of putative transformants. The amenability, authenticity, and reproducibility of soilrite-based kanamycin screening were further verified at the molecular level by GUS histochemical analysis of T0 seedlings, GUS and nptII gene-specific PCR, genomic Southern hybridization for stable integration of T-DNA, and expression analysis of transgenes by sqRT-PCR. This method resulted in a screening efficiency of 6.05% in the presence of kanamycin, indicating amenability of in planta flax transformation. The strategy can be a promising tool for the successful development of transgenics in flax.
Human COVID-19 has affected more than 491 million people worldwide. It has caused over 6.1 million deaths and has especially perpetrated a high number of casualties among the elderly and those with comorbid illnesses. COVID-19 triggers a pro-oxidant response, leading to the production of reactive oxygen species (ROS) as a common innate defense mechanism. However, ROS are regulated by a key enzyme called G6PD via the production of reduced nicotinamide adenine dinucleotide phosphate (NADPH), which controls the generation and removal of ROS in a tissue-specific manner. Therefore, a deficiency of G6PD can lead to the dysregulation of ROS, which causes a severe inflammatory response in COVID-19 patients. This report highlights the G6PD dichotomy in the regulation of ROS and inflammatory responses, as well as its deficiency in severity among COVID-19 patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.