An overview on medicinal perspective of thiazolidine-2,4-dione: A remarkable scaffold in the treatment of type 2 diabetes

•

TZDs, an important pharmacophore in the treatment of diabetes.

•

Various analog-based synthetic strategies and biological significance are discussed.

•

Clinical studies using TZDs along with other antidiabetic agents are also highlighted.

•

SAR has been discussed to suggest the interactions between derivatives and receptor sites.

•

Pyrazole, chromone, and acid-based TZDs can be considered as potential lead molecules.

Diabetes or diabetes mellitus is a complex or polygenic disorder, which is characterized by increased levels of glucose (hyperglycemia) and deficiency in insulin secretion or resistance to insulin over an elongated period in the liver and peripheral tissues. Thiazolidine-2,4-dione (TZD) is a privileged scaffold and an outstanding heterocyclic moiety in the field of drug discovery, which provides various opportunities in exploring this moiety as an antidiabetic agent. In the past few years, various novel synthetic approaches had been undertaken to synthesize different derivatives to explore them as more potent antidiabetic agents with devoid of side effects (i.e., edema, weight gain, and bladder cancer) of clinically used TZD (pioglitazone and rosiglitazone). In this review, an effort has been made to summarize the up to date research work of various synthetic strategies for TZD derivatives as well as their biological significance and clinical studies of TZDs in combination with other category as antidiabetic agents. This review also highlights the structure-activity relationships and the molecular docking studies to convey the interaction of various synthesized novel derivatives with its receptor site.

Structural analysis of missense mutations occurring in the DNA-binding domain of HSF4 associated with congenital cataracts

•

High-resolution structures of wild-type and K23N mutant DBD in HSF4 were determined.

•

Cataract-related mutations in HSF4 were structurally analyzed through MD simulation.

•

Mutations Q61R, K64E, R73H, R116H and R119C likely perturb DNA-binding activity.

•

Mutations K23N, P60H and L114P probably affect trimer formation or folding dynamics.

•

Mutations A19D, H35Y and I86V may be false positives leading to trivial impacts.

Congenital cataract (CC) is the major cause of childish blindness, and nearly 50% of CCs are hereditary disorders. HSF4, a member of the heat shock transcription factor family, acts as a key regulator of cell growth and differentiation during the development of sensory organs. Missense mutations in the HSF4-encoding gene have been reported to cause CC formation; in particular, those occurring within the DNA-binding domain (DBD) are usually autosomal dominant mutations. To address how the identified mutations lead to HSF4 malfunction by placing adverse impacts on protein structure and DNA-binding specificity and affinity, we determined two high-resolution structures of the wild-type DBD and the K23N mutant of human HSF4, built DNA-binding models, conducted in silico mutations and molecular dynamics simulations. Our analysis suggests four possible structural mechanisms underlining the missense mutations in HSF4-DBD and cataractogenesis: (i), disruption of HSE recognition; (ii), perturbation of protein-DNA interactions; (iii), alteration of protein folding; (iv), other impacts, e.g. inhibition of protein oligomerization.

ATAF1 transcription factor directly regulates abscisic acid biosynthetic gene NCED3 in Arabidopsis thaliana

ATAF1, an Arabidopsis thaliana NAC transcription factor, plays important roles in plant adaptation to environmental stress and development. To search for ATAF1 target genes, we used protein binding microarrays and chromatin-immunoprecipitation (ChIP). This identified T[A,C,G]CGT[A,G] and TT[A,C,G]CGT as ATAF1 consensus binding sequences. Co-expression analysis across publicly available microarray experiments identified 25 genes co-expressed with ATAF1. The promoter regions of ATAF1 co-expressors were significantly enriched for ATAF1 binding sites, and TTGCGTA was identified in the promoter of the key abscisic acid (ABA) phytohormone biosynthetic gene NCED3. ChIP-qPCR and expression analysis showed that ATAF1 binding to the NCED3 promoter correlated with increased NCED3 expression and ABA hormone levels. These results indicate that ATAF1 regulates ABA biosynthesis.