@article {46656, title = {Structure and regulation of SWEET transporters in plants: an update}, journal = {Plant Physiology and Biochemistry}, volume = {156}, year = {2020}, month = {NOV}, pages = {1-6}, type = {Review}, abstract = {

Sugar will eventually be exported transporters (SWEETs), a novel family of sugar transporters found in both eukaryotes and prokaryotes, facilitate sugar flux across the cell membrane. Although these transporters were first discovered in plants, their homologs have been reported in different organisms. SWEETs have critical roles in various developmental processes, including phloem loading, nectar secretion, and pathogen nutrition. The structure of bacterial homologs, called SemiSWEETs, has been well studied thus far. Here, we provide an overview of SWEET protein structure and dynamic function by analyzing the solved crystal structures and predicted models that are available for a few SWEETs in a monocot plant (rice) and dicot plant (Arabidopsis thaliana). Despite the advancement in structure-related studies, the regulation of SWEETs remains unknown. In light of reported regulatory mechanisms of a few other sugar transporters, we propose the regulation of SWEETs at the post-translational level. We then enumerate the potential post-translational modification sites in SWEETs using computational tools. Overall, in this review, we critically analyze SWEET protein structure in plants to predict the post-translational regulation of SWEETs. Such findings have a direct bearing on plant nutrition and defense and targeting the regulation at these levels will be important in crop improvement.

}, keywords = {oligomerization, Phosphorylation, Post-translational modification, Sugar transporters, Sugar will eventually be exported transporters}, issn = {0981-9428}, doi = {10.1016/j.plaphy.2020.08.043}, author = {Anjali, Anjali and Fatima, Urooj and Manu, M. S. and Ramasamy, Sureshkumar and Senthil-Kumar, Muthappa} } @article {47371, title = {Extracellular HDAC6 ZnF UBP domain modulates the actin network and post-translational modifications of Tau}, journal = {Cell Communication and Signaling}, volume = {19}, year = {2021}, month = {MAY }, pages = {49}, type = {Article}, abstract = {

Background: Microtubule-associated protein Tau undergoes aggregation in Alzheimer{\textquoteleft}s disease (AD) and a group of other related diseases collectively known as Tauopathies. In AD, Tau forms aggregates, which are deposited intracellularly as neurofibrillary tangles. Histone deacetylase-6 (HDAC6) plays an important role in aggresome formation, where it recruits polyubiquitinated aggregates to the motor protein dynein. Methods: Here, we have studied the effects of HDAC6 ZnF UBP on Tau phosphorylation, ApoE localization, GSK-3 beta regulation and cytoskeletal organization in neuronal cells by immunocytochemical analysis. This analysis reveals that the cell exposure to the UBP-type zinc finger domain of HDAC6 (HDAC6 ZnF UBP) can modulate Tau phosphorylation and actin cytoskeleton organization. Results: HDAC6 ZnF UBP treatment to cells did not affect their viability and resulted in enhanced neurite extension and formation of structures similar to podosomes, lamellipodia and podonuts suggesting the role of this domain in actin re-organization. Also, HDAC6 ZnF UBP treatment caused increase in nuclear localization of ApoE and tubulin localization in microtubule organizing centre (MTOC). Therefore, our studies suggest the regulatory role of this domain in different aspects of neurodegenerative diseases. Upon HDAC6 ZnF UBP treatment, inactive phosphorylated form of GSK-3 beta increases without any change in total GSK-3 beta level. Conclusions: HDAC6 ZnF UBP was found to be involved in cytoskeletal re-organization by modulating actin dynamics and tubulin localization. Overall, our study suggests that ZnF domain of HDAC6 performs various regulatory functions apart from its classical function in aggresome formation in protein misfolding diseases.

}, keywords = {Actin, Cytoskeleton, HDAC6, Microtubule, neurodegeneration, Phosphorylation, Podonut, Podosomes, Tau, Tauopathies}, doi = {10.1186/s12964-021-00736-9}, author = {Balmik, Abhishek Ankur and Sonawane, Shweta Kishor and Chinnathambi, Subashchandrabose} } @article {49127, title = {Inhibitory effect of curcumin-artemisinin co-amorphous on Tau aggregation and Tau phosphorylation}, journal = {Colloid and Surfaces B-Biointerfaces}, volume = {221}, year = {2023}, month = {JAN}, type = {Article}, abstract = {

Tau is a natively unfolded microtubule-associated protein. Tau neurofibrillary tangles are one of the hallmarks of Alzheimer{\textquoteright}s disease. The post-translational modifications of Tau lead to its pathological state. Phosphorylation is the key post-translational modification associated with Tauopathy. Curcumin is a polyphenolic compound pre-sent in the rhizomes of Curcuma longa. Curcumin has been reported to have remarkable medicinal properties in several diseases, but its poor solubility limits its therapeutic potency. Artemisinin is a sesquiterpene lactone, which has been known sience ancient times for its applications as a treatment for various diseases such as malaria, cancer, autoimmune disease, etc. In the present study, the potency of crystalline curcumin, crystalline artemisinin, and Cur-Art co-amorphous dispersion were evaluated against Tau pathology. The in-vitro ThS/ANS fluorescence and electron microscopy results suggested that curcumin and Cur-Art efficiently inhibited Tau aggregation. Furthermore, exposure to curcumin and Cur-Art co-amorphous restored the impaired nuclear transport in formaldehyde-stressed cells. Curcumin was also found to modulate the phosphorylation of Tau, which indicated the neuroprotective potency. Thus, curcumin and Cur-Art co-amorphous exhibit therapeutic potential against Tau protein in Alzheimer{\textquoteright}s disease.

}, keywords = {artemisinin, curcumin, Phosphorylation, Tau Aggregation}, issn = {0927-7765}, doi = {10.1016/j.colsurfb.2022.112970}, author = {Dubey, Tushar and Sonawane, Shweta Kishor and Mannava, M. K. Chaitanya and Nangia, Ashwini K. and Chandrashekar, Madhura and Chinnathambi, Subashchandrabose} }