The porin MspA is a phage-specific determinant of mycobacteriophage infection
- 1Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Solna, Sweden; Science for Life Laboratory, Karolinska Institutet, Solna, Swede
Abstract
Mycobacteriophages are being developed as therapeutics for mycobacterial infections, but their highly variable host ranges limit this application and the bacterial factors that determine whether infection succeeds remain poorly defined. The determinants characterized so far are dominated by cell envelope lipids and glycolipids. Here, we performed a genome-wide CRISPRi screen in Mycobacterium smegmatis to identify host functions associated with susceptibility to BPs{Delta}33HTH HRM10. After prolonged phage challenge, the outer membrane porin genes mspA and mspC were among the most strongly enriched hits, whereas the closely related paralogs mspB and mspD were not enriched despite sharing high amino-acid identity across the family. Deletion of mspA or mspC reduced BPs{Delta}33HTH HRM10 plaque formation and produced smaller, more turbid plaques, with the stronger phenotype following loss of mspA, the major outer membrane porin of M. smegmatis. Across a panel of 25 mycobacteriophages, 11 showed either a more than tenfold reduction in titer or loss of discrete plaque formation on {Delta}mspA, while the remainder were largely unaffected. These findings identify outer membrane porins as phage-dependent determinants of mycobacterial susceptibility, revealing an additional layer of specificity in phage infection beyond previously characterized cell envelope lipids and glycolipids.
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BibTeX
@misc{kim2026porin,
title = {{The porin MspA is a phage-specific determinant of mycobacteriophage infection}},
author = {D. Kim and M. Maziero and K. A. Eckartt and M. A. DeJesus and G. I. Prensa and A. Garcia Navarro and D. R. Parker and P. Santucci and J. M. Rock and A. Fossati},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.08.757660},
url = {https://www.biorxiv.org/content/10.64898/2026.10.08.757660v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - The porin MspA is a phage-specific determinant of mycobacteriophage infection
AU - D. Kim
AU - M. Maziero
AU - K. A. Eckartt
AU - M. A. DeJesus
AU - G. I. Prensa
AU - A. Garcia Navarro
AU - D. R. Parker
AU - P. Santucci
AU - J. M. Rock
AU - A. Fossati
PY - 2026
DA - 2026/10/08
PB - bioRxiv
DO - 10.64898/2026.10.08.757660
UR - https://www.biorxiv.org/content/10.64898/2026.10.08.757660v1
AB - Mycobacteriophages are being developed as therapeutics for mycobacterial infections, but their highly variable host ranges limit this application and the bacterial factors that determine whether infection succeeds remain poorly defined. The determinants characterized so far are dominated by cell envelope lipids and glycolipids. Here, we performed a genome-wide CRISPRi screen in Mycobacterium smegmatis to identify host functions associated with susceptibility to BPs{Delta}33HTH HRM10. After prolonged phage challenge, the outer membrane porin genes mspA and mspC were among the most strongly enriched hits, whereas the closely related paralogs mspB and mspD were not enriched despite sharing high amino-acid identity across the family. Deletion of mspA or mspC reduced BPs{Delta}33HTH HRM10 plaque formation and produced smaller, more turbid plaques, with the stronger phenotype following loss of mspA, the major outer membrane porin of M. smegmatis. Across a panel of 25 mycobacteriophages, 11 showed either a more than tenfold reduction in titer or loss of discrete plaque formation on {Delta}mspA, while the remainder were largely unaffected. These findings identify outer membrane porins as phage-dependent determinants of mycobacterial susceptibility, revealing an additional layer of specificity in phage infection beyond previously characterized cell envelope lipids and glycolipids.
ER -