scholarly journals Plasmodium falciparum Atg18 localizes to the food vacuole via interaction with the multi-drug resistance protein 1 and phosphatidylinositol 3-phosphate

2021 ◽  
Author(s):  
Renu Sudhakar ◽  
Divya Das ◽  
Subramanian Thanumalayan ◽  
Somesh Gorde ◽  
Puran Singh Sijwali
Keyword(s):  
Drug Resistance ◽  
Critical Role ◽  
Food Vacuole ◽  
Multi Drug Resistance ◽  
Feature Interaction ◽  
Cytoplasmic Localization ◽  
Wild Type ◽  
Transport Pathway ◽  
Binding Motifs ◽  
Resistance Protein

Autophagy, a lysosome-dependent degradative process, does not appear to be a major degradative process in malaria parasites and has a limited repertoire of genes. To better understand the autophagy process, we investigated Plasmodiumfalciparum Atg18 (PfAtg18), a PROPPIN family protein, whose members like S. cerevisiae Atg18 (ScAtg18) and human WIPI2 bind PI3P and play an essential role in autophagosome formation. Wild type and mutant PfAtg18 were expressed in P. falciparum and assessed for localization, the effect of various inhibitors and antimalarials on PfAtg18 localization, and identification of PfAtg18-interacting proteins. PfAtg18 is expressed in asexual erythrocytic stages and localized to the food vacuole, which was also observed with other Plasmodium Atg18 proteins, indicating that food vacuole localization is likely a shared feature. Interaction of PfAtg18 with the food vacuole-associated PI3P is essential for localization, as PfAtg18 mutants of PI3P-binding motifs neither bound PI3P nor localized to the food vacuole. Interestingly, wild type ScAtg18 interacted with PI3P, but its expression in P. falciparum showed complete cytoplasmic localization, indicating additional requirement for food vacuole localization. The food vacuole multi-drug resistance protein 1 (MDR1) was consistently identified in the immunoprecipitates of PfAtg18 and P. berghei Atg18, and also interacted with PfAtg18. In contrast to PfAtg18, ScAtg18 did not interact with MDR1, which, in addition to PI3P, could play a critical role in localization of PfAtg18. Chloroquine and amodiaquine caused cytoplasmic localization of PfAtg18, suggesting that these target PfAtg18 transport pathway. Thus, PI3P and MDR1 are critical mediators of PfAtg18 localization.

scholarly journals Plasmodium falciparum Atg18 localization to the food vacuole is phosphatidylinositol 3- phosphate-dependent and quinoline-sensitive

2020 ◽  
Author(s):  
Renu Sudhakar ◽  
Divya Das ◽  
Subramanian Thanumalayan ◽  
Puran Singh Sijwali
Keyword(s):  
Drug Resistance ◽  
Food Vacuole ◽  
Multi Drug Resistance ◽  
Feature Interaction ◽  
Binding Motifs ◽  
Family Protein ◽  
Potential Link ◽  
Resistance Protein ◽  
A Site ◽  
Phosphatidylinositol 3

AbstractMalaria parasites exhibit atypical, but essential, autophagy process, which is also associated with resistance to chloroquine and artemisinin. To better understand the autophagy process and its association with drug resistance, we investigated P. falciparum Atg18 (PfAtg18), a PROPPIN family protein, whose members like S. cerevisiae Atg18 and human WIPI2 are essential for autophagy. PfAtg18 and its mutants were expressed in P. falciparum and assessed for localization and co-localization, the effect of various inhibitors and antimalarials on PfAtg18 localization, and to identify PfAtg18-interacting proteins. PfAtg18 is expressed in asexual erythrocytic stages and localized to the food vacuole, which was also observed with other Plasmodium Atg18 proteins, indicating that food vacuole localization is a conserved feature. Interaction of PfAtg18 with the food vacuole-associated phosphatidylinositol 3-phosphate (PI3P) is essential for localization, as PfAtg18 mutants of PI3P-binding motifs neither bound PI3P nor localized to the food vacuole. PfAtg18 also interacted with the food vacuole multi-drug resistance protein 1, which, in addition to PI3P, could play a major role in localization of PfAtg18. PfAtg18 interacted and co-localized with P. falciparum Atg8 at a peri-food vacuole site, which may be a site for generation of PfAtg8 puncta. PfAtg18 localization was greatly affected upon treatment with chloroquine and amodiaquine, suggesting that these quinolines target PfAtg18 or the proteins that might be involved in its localization. Food vacuole localization, altered localization upon treatment with chloroquine and amodiaquine, and interaction with the multi-drug resistance protein 1 present PfAtg18 as a potential link between autophagy and the associated drug resistance.

scholarly journals Mechanism of Darunavir (DRV)’s High Genetic Barrier to HIV-1 Resistance: A Key V32I Substitution in Protease Rarely Occurs, but Once It Occurs, It Predisposes HIV-1 To Develop DRV Resistance

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Manabu Aoki ◽  
Debananda Das ◽  
Hironori Hayashi ◽  
Hiromi Aoki-Ogata ◽  
Yuki Takamatsu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Amino Acid ◽  
Critical Role ◽  
Viral Fitness ◽  
Single Amino Acid ◽  
Amino Acid Substitutions ◽  
Wild Type ◽  
Genetic Barrier ◽  
High Level ◽  
Hiv 1

ABSTRACTDarunavir (DRV) has bimodal activity against HIV-1 protease, enzymatic inhibition and protease dimerization inhibition, and has an extremely high genetic barrier against development of drug resistance. We previously generated a highly DRV-resistant HIV-1 variant (HIVDRVRP51). We also reported that four amino acid substitutions (V32I, L33F, I54M, and I84V) identified in the protease of HIVDRVRP51are largely responsible for its high-level resistance to DRV. Here, we attempted to elucidate the role of each of the four amino acid substitutions in the development of DRV resistance. We found that V32I is a key substitution, which rarely occurs, but once it occurs, it predisposes HIV-1 to develop high-level DRV resistance. When two infectious recombinant HIV-1 clones carrying I54M and I84V (rHIVI54Mand rHIVI84V, respectively) were selected in the presence of DRV, V32I emerged, and the virus rapidly developed high-level DRV resistance. rHIVV32Ialso developed high-level DRV resistance. However, wild-type HIVNL4-3(rHIVWT) failed to acquire V32I and did not develop DRV resistance. Compared to rHIVWT, rHIVV32Iwas highly susceptible to DRV and had significantly reduced fitness, explaining why V32I did not emerge upon selection of rHIVWTwith DRV. When the only substitution is at residue 32, structural analysis revealed much stronger van der Waals interactions between DRV and I-32 than between DRV and V-32. These results suggest that V32I is a critical amino acid substitution in multiple pathways toward HIV-1’s DRV resistance development and elucidate, at least in part, a mechanism of DRV’s high genetic barrier to development of drug resistance. The results also show that attention should be paid to the initiation or continuation of DRV-containing regimens in people with HIV-1 containing the V32I substitution.IMPORTANCEDarunavir (DRV) is the only protease inhibitor (PI) recommended as a first-line therapeutic and represents the most widely used PI for treating HIV-1-infected individuals. DRV possesses a high genetic barrier to development of HIV-1’s drug resistance. However, the mechanism(s) of the DRV’s high genetic barrier remains unclear. Here, we show that the preexistence of certain single amino acid substitutions such as V32I, I54M, A71V, and I84V in HIV-1 protease facilitates the development of high-level DRV resistance. Interestingly, allin vitro-selected highly DRV-resistant HIV-1 variants acquired V32I but never emerged in wild-type HIV (HIVWT), and V32I itself rendered HIV-1 more sensitive to DRV and reduced viral fitness compared to HIVWT, strongly suggesting that the emergence of V32I plays a critical role in the development of HIV-1’s resistance to DRV. Our results would be of benefit in the treatment of HIV-1-infected patients receiving DRV-containing regimens.

scholarly journals High resolution melting analysis and detection of Leishmania resistance: the role of multi drug resistance 1 gene

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Maryam Fekri Soofi Abadi ◽  
Alireza Moradabadi ◽  
Reza Vahidi ◽  
Saeedeh Shojaeepour ◽  
Sara Rostami ◽  
...  
Keyword(s):  
Drug Resistance ◽  
High Resolution ◽  
High Resolution Melting ◽  
Efflux Pump ◽  
Mdr1 Gene ◽  
Multi Drug Resistance ◽  
Sequencing Method ◽  
Melting Analysis ◽  
Resistance Protein

Abstract Background Pentavalent antimonial compounds are currently used to treat leishmaniasis and resistance to these drugs is a serious problem. Multidrug resistance protein is an efflux pump of the cell membrane that expels foreign compounds. This study designed to evaluate the mutations in the multi-drug resistance 1 (MDR1) gene, in biopsy specimens of Leishmania tropica, with high resolution melting (HRM) method. In this experimental study, genomic DNA was extracted from 130 patients with skin leishmaniasis. Then, nucleotide changes were investigated throughout the gene using HRM and sequencing methods. The samples categorized in 5 groups by differences in the melting temperature (Tm). Result The nucleotide changes analysis showed that 61% of the samples of different groups that were unresponsive to drug had mutations in the MDR1 gene, which were also confirmed by the sequencing method. These mutations can be one of the factors responsible for non-responsiveness to the treatment. Conclusion According to the findings, it seems that mutation in MDR1 gene could be responsible for drug resistance to pentavalent antimonial compounds. Furthermore, HRM method can be used to diagnose drug resistance in leishmaniasis. It is also recommended that further studies be done regarding the importance of drug resistance in the leishmania affected patients.

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