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Shivani, K.

Publications and source records attributed to Shivani, K..

2 recordsLinked to original sources
bioRxiv2026

A high-quality chromosome-scale reference genome assembly for Asparagus racemosus var. CIM-Shakti (Shatavari), a medicinal plant of Ayurvedic importance

Asparagus racemosus Wild., commonly known as Shatavari, is an important medicinal plant in Ayurveda and is valued for its steroidal saponins, particularly shatavarin compounds, which contribute to its adaptogenic, galactagogue, immunomodulatory, and therapeutic properties. Despite its medicinal and economic importance, genomic resources for this species have remained limited, restricting molecular breeding, pathway discovery, and comparative evolutionary studies within Asparagaceae. Here, we report a high quality chromosome scale reference genome assembly of A. racemosus var. CIM Shakti generated using PacBio HiFi long read sequencing and Omni C chromatin conformation scaffolding. The pseudo haploid assembly spans 817 Mb across 53 scaffolds, with a scaffold N50 of 98.50 Mb, L50 of 5, and a largest scaffold of 113.80 Mb. Ten major chromosome scale pseudomolecules were resolved, corresponding to the haploid chromosome complement of A. racemosus. The assembly showed high gene space completeness, with BUSCO completeness of 99.8% against the Eukaryota dataset and 98.0% against the Embryophyta dataset. BlobToolKit profiling further supported assembly quality, with GC content of approximately 39 to 40% and no major evidence of contamination. EDTA based repeat annotation identified 580.93 Mb of interspersed repetitive elements, accounting for 71.06% of the 817.57 Mb genome assembly. The repeat landscape was dominated by LTR retrotransposons, particularly Gypsy elements, which accounted for 25.01% of the assembly, followed by unclassified LTR elements at 26.58% and Copia elements at 4.84%. Structural and functional annotation identified 29,199 protein coding genes represented by 29,199 transcript models, 138,433 exons, and 125,201 CDS features. The annotation was structurally robust, with an average gene length of 4,605.1 bp, 4.74 exons per transcript, and 97.80% of transcripts containing multiple exons. The CIM Shakti reference genome provides a foundational genomic resource for investigating steroidal saponin biosynthesis, sex chromosome evolution, repeat driven genome expansion, and comparative genomics in Asparagaceae. This assembly will support future studies on medicinal trait improvement, conservation genomics, and genomics assisted breeding of climate resilient Shatavari cultivars.

bioinformatics↗
bioRxiv2026

Residue-specific dominant-negative mutant of ubiquitin reveals functional selectivity as Ubp14 deubiquitinase inhibitor

Multifunctional proteins encode specificity through nuanced molecular interactions that operate in the presence of abundant wild-type molecules. Previous studies on multifunctional proteins have shown how certain regulated interactions parse complex biological activities into discrete functional modules. Discrete interaction edges can function as regulatory nodes whose perturbations selectively remodel proteostasis output, especially under disease conditions. However, whether such interaction specificity can be harnessed to selectively manipulate functional modules and reveal residue-level control principles, remains largely unexplored. Here, we screened for dominant negative mutations that impact partner-selective functions linked to Leu8, a critical binding residue on ubiquitin. Our results reveal that the Leu8Ala mutation specifically leads to accumulation of polyubiquitinated proteins and decreased levels of free ubiquitin suggesting loss of deubiquitinase function in yeast cells. Cellular and biochemical analyses establish that the Leu8Ala variant of ubiquitin specifically inhibits the yeast deubiquitinase, Ubp14, and its human homolog, USP5. We further demonstrate remodelling of the binding interface with increased interface contacts for the variant and Ubp14 complex. The variant shows a higher inhibitory potency compared to the wild-type ubiquitin and can inhibit Ubp14 both as unconjugated and as conjugated ubiquitin chain indicating the strength of its inhibitory function. Our results provide mechanistic insight into how edge perturbations in ubiquitin can reveal critical nodes that impact selective functions and thus fine-tune the cellular proteostasis network for therapeutic benefit.

biochemistry↗