Journal of Microbiology

Journal Article

Transcript-specific selective translation by specialized ribosomes bearing genome-encoded heterogeneous rRNAs in V. vulnificus CMCP6: Younkyung Choi , Minju Joo , Wooseok Song , Minho Lee , Hana Hyeon , Hyun-Lee Kim , Ji-Hyun Yeom , Kangseok Lee , Eunkyoung Shin; J. Microbiol. 2022;60(12):1162-1167. Published online November 24, 2022; DOI: https://doi.org/10.1007/s12275-022-2437-9

Abstract: Ribosomes composed of genome-encoded heterogeneous rRNAs are implicated in the rapid adaptation of bacterial cells to environmental changes. A previous study showed that ribosomes bearing the most heterogeneous rRNAs expressed from the rrnI operon (I-ribosomes) are implicated in the preferential translation of a subset of mRNAs, including hspA and tpiA, in Vibrio vulnificus CMCP6. In this study, we show that HspA nascent peptides were predominantly bound to I-ribosomes. Specifically, I-ribosomes were enriched more than two-fold in ribosomes that were pulled down by immunoprecipitation of HspA peptides compared with the proportion of I-ribosomes in crude ribosomes and ribosomes pulled down by immunoprecipitation of RNA polymerase subunit ß peptides in the wild-type (WT) and rrnI-completed strains. Other methods that utilized the incorporation of an affinity tag in 23S rRNA or chimeric rRNA tethering 16S and 23S rRNAs, which generated specialized functional ribosomes in Escherichia coli, did not result in functional I-ribosomes in V. vulnificus CMCP6. This study provides direct evidence of the preferential translation of hspA mRNA by I-ribosomes.

Review

Protective and pathogenic role of humoral responses in COVID-19: Uni Park , Nam-Hyuk Cho; J. Microbiol. 2022;60(3):268-275. Published online March 2, 2022; DOI: https://doi.org/10.1007/s12275-022-2037-8

Abstract: Since the advent of SARS-CoV-2 in Dec. 2019, the global endeavor to identify the pathogenic mechanism of COVID-19 has been ongoing. Although humoral immunity including neutralizing activity play an important role in protection from the viral pathogen, dysregulated antibody responses may be associated with the pathogenic progression of COVID-19, especially in high-risk individuals. In addition, SARS-CoV-2 spike-specific antibodies acquired by prior infection or vaccination act as immune pressure, driving continuous population turnover by selecting for antibody-escaping mutations. Here, we review accumulating knowledge on the potential role of humoral immune responses in COVID-19, primarily focusing on their beneficial and pathogenic properties. Understanding the multifaceted regulatory mechanisms of humoral responses during SARS-CoV-2 infection can help us to develop more effective therapeutics, as well as protective measures against the ongoing pandemic.

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