Biology subjects

Kadandale, P.

Publications and source records attributed to Kadandale, P..

4 recordsLinked to original sources

bioRxiv2021

Identifying The "Core" Transcriptome of SARS-CoV-2 Infected Cells

In 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first emerged, causing the COVID-19 pandemic. Consequently, ongoing research has focused on better understanding the mechanisms underlying the symptoms of this disease. Although COVID-19 symptoms span a range of organ systems, the specific changes in gene regulation that lead to the variety of symptoms are still unclear. In our study, we used publicly available transcriptome data from previous studies on SARS-CoV-2 to identify commonly regulated genes across cardiomyocytes, human bronchial epithelial cells, alveolar type II cells, lung adenocarcinoma, human embryonic kidney cells, and patient samples. Additionally, using this common "core" transcriptome, we could identify the genes that were specifically and uniquely regulated in bronchial epithelial cells, embryonic kidney cells, or cardiomyocytes. For example, we found that genes related to cell metabolism were uniquely upregulated in kidney cells, providing us with the first mechanistic clue about specifically how kidney cells may be affected by SARS-CoV-2. Overall, our results uncover connections between the differential gene regulation in various cell types in response to the SARS-CoV-2 infection and help identify targets of potential therapeutics.

bioinformatics↗

bioRxiv2021

Course-based Undergraduate Research Module for Enzyme Discovery Using Protein Structure Prediction

A major challenge for science educators is teaching foundational concepts while introducing their students to current research. Here we describe an active learning module developed to teach protein structure fundamentals while supporting ongoing research in enzyme discovery. It can be readily implemented in both entry-level and upper-division college biochemistry or biophysics courses. Pre-activity lectures introduced fundamentals of protein secondary structure and provided context for the research projects, while a homework assignment familiarized students with 3D visualization of biomolecules using UCSF Chimera, a free protein structure viewer. The activity is an online survey in which students compare structure elements in papain, a well-characterized cysteine protease from Carica papaya, to novel homologous proteases identified from the genomes of an extremophilic microbe (Halanaerobium praevalens) and two carnivorous plants (Drosera capensis and Cephalotus follicularis). Students were then able to identify, with varying levels of accuracy, a number of structural features in cysteine proteases that could expedite the identification of novel or biochemically interesting cysteine proteases for experimental validation in a university laboratory. Student responses to a post-activity survey were largely positive and constructive, describing points in the activity that could be improved and indicating that the activity helped them learn about protein structure.

scientific communication and education↗

bioRxiv2021

Comparing Expression of OAS-RNaseL Pathway-Related Genes in SARS-CoV-2 and Similar Viruses

The COVID-19 pandemic, caused by the virus SARS-CoV-2, has been a major public health emergency and has caused millions of deaths worldwide to date. Due to the novel nature of the virus, efforts across the world are underway to better understand the molecular pathogenesis of SARS-CoV-2 and how it interacts with host immune responses. One important branch of the innate immune response, the interferon system, triggers the expression of many effector mechanisms known to be powerful antagonists against many pathogenic viruses. One such interferon stimulated mechanism is the OAS-RNaseL pathway, which is known to trigger the degradation of viral RNA in infected host cells. Our study seeks to utilize publicly available transcriptomic data to analyze the host cell OAS-RNaseL pathway to SARS-CoV-2 infection. We hoped to gain an understanding of the importance of the pathway in controlling SARS-CoV-2 infection and whether or not the pathway could be exploited therapeutically. Our findings demonstrated that upregulation of OAS-RNaseL pathway genes in response to SARS-CoV-2 infection varies based on cell type and appeared to correlate with ACE2 receptor expression. Pathway responses to other viruses like SARS-CoV and MERS-CoV were found to parallel those to SARS-CoV-2, suggesting common response patterns by the pathway to these viruses. Overall, these results demonstrate that the OAS-RNaseL pathway could contribute to control of SARS-CoV-2 infection. Further studies on various mechanistic actions by the pathway would need to be conducted to fully understand its role in host defense and therapy.

immunology↗

bioRxiv2017

MicroRNA miR-128 represses LINE-1 (L1) retrotransposition by downregulating the nuclear import factor TNPO1

Repetitive elements, including LINE-1 (L1), comprise approximately half of the human genome. These elements can potentially destabilize the genome by initiating their own replication and reintegration into new sites (retrotransposition). In somatic cells, transcription of L1 elements are repressed by distinct molecular mechanisms including DNA methylation and histone modifications to repress transcription. Under conditions of hypomethylation (e.g. in tumor cells) a window of opportunity for L1 de-repression arises and additional restriction mechanisms become crucial. We recently demonstrated that the microRNA miR-128 represses L1 activity by directly binding to L1 ORF2 RNA. In this study, we tested whether miR-128 can also control L1 activity by repressing cellular proteins important for L1 retrotransposition. We found that miR-128 targets the 3UTR of the nuclear import factor transportin 1 (TNPO1) mRNA. Manipulation of miR-128 and TNPO1 levels demonstrated that induction or depletion of TNPO1 affects L1 retrotransposition and nuclear import of an L1-RNP complex (using L1-encoded ORF1p as a proxy for L1-RNP complexes). Moreover, TNPO1 overexpression partially reversed the repressive effect of miR-128 on L1 retrotransposition. Our study represents the first description of a protein factor involved in nuclear import of the L1 element and demonstrates that miR-128 controls L1 activity in somatic cells through two independent mechanisms: direct binding to L1 RNA, and regulating a cellular factor necessary for L1 nuclear import and retrotransposition.

cell biology↗