Biology subjects

Yadala, R.

Publications and source records attributed to Yadala, R..

4 recordsLinked to original sources

bioRxiv2026

Combined celecoxib and NDGA induces a non-canonical, autophagy-independent redox cell death via p62/KEAP1 in colorectal cancer

Colorectal cancer (CRC) exhibits substantial intratumoral heterogeneity, with differences in oncogenic driver mutations and apoptotic competence contributing to therapeutic resistance. Here, we investigated whether combined celecoxib and NDGA treatment (C+N) induces redox-mediated cell death via the p62/KEAP1 axis, offering a therapeutic approach that can overcome genetic diversity in CRC. We used two genetically distinct CRC cell lines, HCT116 and HT29, harbouring KRAS and BRAF mutations respectively, with differing p53 status, as models of tumor heterogeneity. C+N exhibited profound cytotoxicity in both cell lines, independent of COX-2/5-LOX expression and apoptotic competence. Additionally, C+N induced marked oxidative stress with mitochondrial ROS, lipid peroxidation, and labile ferrous iron accumulation, visualized as distinct JC-1 green mitochondrial puncta and FerroOrange red iron puncta in both cell lines. The antioxidant NAC reversed C+N-induced death, but inhibitors of apoptosis, autophagy, necroptosis, or ferroptosis did not, indicating a mechanism distinct from these pathways. Mechanistically, the combination induced p62 Ser349 phosphorylation, promoting KEAP1 degradation and NRF2 stabilization independently of ULK1-mediated autophagy; however, NRF2 stabilization was uncoupled from HO-1 induction. Our work reveals that C+N induces a ULK1/autophagy-independent, redox-mediated cell death mechanism that circumvents apoptotic competence, highlighting redox disruption as a genotype-independent therapeutic strategy to overcome CRC heterogeneity.

cancer biology↗

bioRxiv2024

Structural Basis of betaKNL2 Centromeric Targeting Mechanism and Its Role in Plant-Specific Kinetochore Assembly

The kinetochore is an essential protein complex that ensures proper chromosome segregation during cell division. Kinetochore assembly is initiated by the incorporation of CENP-A/CENH3. This process depends on KNL2/M18BP1 and CENP-C proteins. In plants, two variants of KNL2, KNL2 and {beta}KNL2, are present. Both possess the conserved SANTA domain, while KNL2 additionally has the centromere-targeting CENPC-k motif. Despite lacking the CENPC-like motif, the plant-specific {beta}KNL2 localizes to centromeres and aids in CENP-A/CENH3 loading. We found that efficient centromeric targeting of {beta}KNL2 requires the SANTA domain and the C-terminal part, while nuclear targeting depends on a conserved C-terminal motif-III. Structural predictions and experimental validations reveal that {beta}KNL2 forms homodimers and interacts with centromeric DNA and KNL2. We confirm that centromeric targeting of {beta}KNL2 depends on KNL2 in a tissue-dependent manner. Our findings provide crucial insights into the unique mechanisms of plant-specific kinetochore assembly, highlighting {beta}KNL2s essential role in this process. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/605747v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@30b331org.highwire.dtl.DTLVardef@14494a3org.highwire.dtl.DTLVardef@17a6336org.highwire.dtl.DTLVardef@7ad8f_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2024

Centromeric localization of KNL2 and CENP-C proteins in plants depends on their centromere-targeting domain and DNA-binding regions

In eukaryotic organisms, proper chromosome segregation during cell division depends on the centromeric histone H3 (CENH3) variant. Our previous studies identified a plant CENH3 assembly factor, Kinetochore Null2 (KNL2), that possesses a centromere-targeting motif, CENPC-k, similar to the CENPC motif in CENP-C. Additionally, we have demonstrated that KNL2 can bind DNA in vitro, independent of its CENPC-k motif. Thus, the mechanism underlying the binding of KNL2 to centromeric DNA remains elusive. Our study shows that the CENPC-k and CENPC motifs alone are not sufficient to target the centromere in N. benthamiana and A. thaliana. In-silico analysis revealed flanking DNA-binding regions near the CENPC-k and CENPC motifs, suggesting their importance in interacting with centromeric DNA. Fusion of protein fragments containing these motifs to EYFP facilitated targeting to the centromere. Deletion of DNA-binding domains reduced the centromeric localization of KNL2-C, whereas fusion of CENPC-k to the H-NS protein from E. coli targeted it to centromeres. We conclude that targeting of KNL2 and CENP-C proteins to centromeres is dependent on the CENPC-k/CENPC motifs, and their sequence-independent DNA-binding promotes anchoring at the centromere. Understanding the targeting mechanisms of KNL2 and CENP-C may help to engineer kinetochore structure by targeting chromatin modifying proteins to centromeres.

plant biology↗

bioRxiv2022

Integrative Multi-Omics Approaches for Identifying Cervical Cancer Therapeutic Targets

After breast cancer, cervical cancer (CC) is one of the most common malignancies in women globally. Over 90% of chronic infections are caused by human papillomavirus (HPV) and its subtypes. Extensive research efforts are required to identify the treatment targets and prognostic indicators for recurring and metastatic cancers. It may be possible because of omics methods, including genomes, epigenomics, transcriptomics, proteomics, and metabolomics. High throughput (HT) data on the differential mRNA and miRNA expression and their crucial interrelationships enable promising integration and interpretation of the results. Clinical data and multi-omics have risen to the top of the heap in delivering molecular and cellular activities. They aid in comparing data from different omics approaches and bridging the gap between genotype and phenotype. Therefore, multi-omic techniques may improve the knowledge of the molecular basis of the physiology and primary cause of disease, revealing a new route for the prognosis, diagnosis, prevention, and therapy of human diseases.

systems biology↗