Biology subjects

Chawla, A. K.

Publications and source records attributed to Chawla, A. K..

3 recordsLinked to original sources

bioRxiv2026

Reversible RNA Acylating Reagents with Nitro Reduction Strategy

We developed a series of nitro reduction-reversible acylating reagents. Following optimization of the acylation conditions, these reagents were tested for deacylation with sodium dithionite in vitro. We applied this reversible acylation to modulate RNAzyme-mediated pre-tRNA maturation, demonstrating its ability to regulate RNA-RNA interactions. Furthermore, the in vitro reversible acylation of EGFP mRNA indicated effective control of its translational activity. To explore cellular applications, we validated NQO1-mediated deacylation in vitro and then induced hypoxia in HepG2 cells using cobalt chloride, thereby reactivating the function of acylated EGFP mRNA via endogenous NQO1. Overall, this study highlights the potential for developing nitro reduction-reversible acylation as a new strategy for RNA functional control and RNA-based drug modification.

biochemistry↗

bioRxiv2026

The Shape of Control: How Going in Circles Keeps RNA Catalytically Switched On

RNase P was one of the first enzymes discovered to have an RNA-based catalytic component. Since its identification, it has been extensively studied, particularly in E. coli, due to the ability of its M1 RNA to exhibit in vitro catalytic activity even in the absence of associated protein. In this study, we report G-quadruplex formation as a potential regulatory mechanism that modulates the catalytic activity of this RNA. We observed a significantly higher propensity for G-quadruplex formation in the linear isoform (linM1) compared to its circular counterpart (circM1). G-quadruplex formation was confirmed through circular dichroism spectroscopy and a fluorescence-based assay using a G-quadruplex-binding small molecule. We compared the catalytic activity of linM1 and circM1 in lithium and potassium environments and found that G-quadruplex formation specifically reduced linM1 activity. Furthermore, we observed distinct condensate properties of linM1 in the presence or absence of G-quadruplex structures. Overall, our findings suggest that G-quadruplex formation serves as a regulatory switch for RNA activity in linM1, whereas circM1 resists G-quadruplex formation and remains catalytically active even under conditions that favor G-quadruplex assembly.

biochemistry↗

bioRxiv2025

Unlocking efficiency: Native circular RNA surpass linear isoforms in RNase P activity

RNase P, one of the earliest enzymes identified with RNA as its catalytic component, has been extensively studied across all three domains of life. In this research, we unveil circular isoforms of RNase P RNA within bacterial, fungal, and human cell lines. Comparing the bacterial variant, circM1, with its linear counterpart under diverse conditions revealed its enhanced temperature resistance and superior tolerance to Mn2+. Moreover, our findings suggest distinct protein associations for both isoforms in the presence of FBS. The human counterpart, circH1, was proved to be active in cellulo.

cell biology↗