Biology subjects

Serwa, R. A.

Publications and source records attributed to Serwa, R. A..

6 recordsLinked to original sources

bioRxiv2026

A host ATPase essential for rhinovirus replication is an antiviral target with a high barrier to resistance

Rhinoviruses are the leading cause of acute respiratory illnesses and comprise more than 170 types that constantly circulate in humans worldwide. Beyond common colds, rhinoviruses can trigger severe symptoms, particularly in young children, older adults and people with asthma or chronic obstructive pulmonary disease. Despite their clinical and socio-economic impact, no approved vaccine or antiviral treatment exist. Here, we uncovered the interaction of the host AAA+ ATPase RUVBL1/2 with rhinovirus non-structural protein 2C and we demonstrated that RUVBL1/2 is strictly and specifically required for the replication of the viral RNA of the most prevalent and pathogenic rhinovirus species. Pharmacological inhibition of RUVBL1/2 ATPase activity efficiently inhibited rhinovirus replication in a human nasal epithelium model, even post-infection. Moreover, serial viral passaging in the presence of a RUVBL1/2 inhibitor did not lead to the emergence of resistance. These findings reveal an unexpected and strong host dependency with promising potential for antiviral targeting.

microbiology↗

bioRxiv2024

Depletion of essential GroEL protein in Escherichia coli using Clp-Interacting Peptidic Protein Erasers (CLIPPERs)

New, universal tools for targeted protein degradation in bacteria can help to accelerate protein function studies and antimicrobial research. We have developed a new method for degrading bacterial proteins using plasmid-encoded degrader peptides which deliver target proteins for degradation by a highly conserved ClpXP protease. We demonstrated the mode of action of the degraders on a challenging essential target, GroEL. The studies in bacteria were complemented by in vitro binding and structural studies. Expression of degrader peptides resulted in a temperature-dependent growth inhibition and depletion of GroEL levels over time. The reduction of GroEL levels was accompanied by dramatic proteome alterations. The presented method offers a new alternative approach for regulating protein levels in bacteria without genomic modifications or tag fusions. Our studies demonstrate that ClpXP is an attractive protease for the future use in bacterial targeted protein degradation.

molecular biology↗

bioRxiv2023

Sterility-Independent Enhancement of Proteasome Function via Floxuridine-Triggered Detoxification in C. elegans

The ubiquitin-proteasome system (UPS) functionality is vital for proteostasis, contributing to stress resilience, lifespan, and thermal adaptability. In Caenorhabditis elegans, proteasome constituents such as the RPN-6 and PBS-6 subunits or the PSME-3 activator are respectively linked to heat resistance, survival at low temperatures (4{degrees}C), and longevity at moderate cold (15{degrees}C). Since the inhibition of germline stem cells proliferation is associated with robust proteostasis in worms, we utilized floxuridine (FUdR), a compound known for inducing sterility, to examine whether it could reinforce UPS under proteasome dysfunction, particularly to foster cold survival. We demonstrate that FUdR promotes proteasome resilience during its inhibition or subunit deficits, supporting normal lifespan and facilitating adaptation to cold. FUdRs elevation of the UPS activity occurs independently of main proteostasis regulators and is partly driven by SKN-1-regulated transcription, especially under reduced proteasome function. Additionally, we uncover a FUdR-stimulated detoxification pathway, distinct from both SKN-1 and the germline, with GST-24 emerging as a critical mediator of the UPS buffering. This research underscores FUdRs role in the UPS modulation and its contribution to survival of worms in low-temperature conditions. HIGHLIGHTSO_LIFloxuridine (FUdR) enhances ubiquitin-proteasome system activity in C. elegans, independent of primary proteostasis regulators. C_LIO_LIFUdR permits worms to maintain a normal lifespan and facilitates their adaptation to cold in the context of proteasome deficits. C_LIO_LIActing independently of the germline and SKN-1, FUdR triggers a detoxification pathway, with GST-24 as a pivotal component in modulating the ubiquitin-proteasome system. C_LI

molecular biology↗

bioRxiv2023

OMA1 protease eliminates arrested protein import intermediates upon depolarization of the inner mitochondrial membrane.

Most mitochondrial proteins originate from the cytosol and require active transport into the organelle. Such precursor proteins must be largely unfolded to pass through translocation channels in mitochondrial membranes. Misfolding of transported proteins can result in their arrest and translocation failure. Arrested proteins block further import, disturbing mitochondrial functions and cellular proteostasis. Cellular responses to translocation failure have been defined in yeast. To discover molecular mechanisms that resolve failed import events in human cells, we developed the translocase clogging model using a fusion protein with a rigid domain. The mechanism we uncover differs significantly from these described in fungi, where ATPase-driven extraction of blocked protein is directly coupled with proteasomal processing. We found human cells to rely primarily on mitochondrial factors to clear translocation channel blockage. The mitochondrial membrane depolarization triggered proteolytic cleavage of the stalled protein, which involved mitochondrial protease OMA1. The cleavage allowed releasing the protein fragment that blocked the translocase. The released fragment was further cleared in the cytosol by the valosin containing protein (VCP)/p97 and proteasome.

molecular biology↗

bioRxiv2021

Protein homeostasis is maintained by proteasomes containing PSMB9 induced by EEF1A2 upon mitochondrial stress

Perturbed proteostasis and mitochondrial dysfunction are often associated with age-related diseases such as Alzheimers and Parkinsons diseases. However, the link between them remains incompletely understood. Mitochondrial dysfunction causes proteostasis imbalance, and cells respond to restore proteostasis by increasing proteasome activity and molecular chaperons in yeast and C. elegans. Here, we demonstrate the presence of similar responses in humans. Mitochondrial dysfunction upregulates a small heat shock protein HSPB1 and an immunoproteasome subunit PSMB9 leading to an increase in proteasome activity. HSPB1 and PSMB9 are required to prevent protein aggregation upon mitochondrial dysfunction. Moreover, PSMB9 expression is dependent on a translation elongation factor EEF1A2, and PSMB9-containing proteasomes are located near mitochondria, enabling fast local degradation of aberrant proteins. Our findings put a step forward in understanding the stress response triggered by mitochondrial dysfunction, and may be useful for therapeutic strategies to prevent or delay the onset of age-related diseases and attenuate their progression.

cell biology↗

bioRxiv2020

Ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) is a novel metazoan specific complex III assembly factor

Assembly of the dimeric complex III (CIII2) in the mitochondrial inner membrane is an intricate process in which many factors are involved. Despite many studies this process is yet to be completely understood. Here we report the identification of human OCIAD2 (Ovarian Carcinoma Immunoreactive Antigen domain containing protein 2) protein as an assembly factor for CIII2. OCIAD2 was found deregulated in several carcinomas and in some neurodegenerative disorders; however its non-pathological role was not elucidated to date. We have shown that OCIAD2 localizes to mitochondria and interacts with electron transport chain (ETC) proteins. Complete loss of OCIAD2 using gene editing in HEK293 cells resulted in abnormal mitochondrial morphology, decrease assembly of both CIII2 and supercomplex III2+IV and decreased activities of complex I and III. Identification of OCIAD2 as a protein required for assembly of functional CIII2 provides a new insight into the biogenesis and architecture of the ETC. Elucidating the mechanism of OCIAD2 action is important both for the understanding of cellular metabolism and for understanding of its role in the malignant transformation.

cell biology↗