Pseudogene Recoding Revealed from Proteomic Analysis of <i>Salmonella</i> Serovars

Recoding refers to the reprogramming of mRNA translation by nonstandard read-out rules. In this study, we used stable isotope labeling with amino acids in cell culture (SILAC) technology to investigate the proteome of host-adapted Salmonella serovars, which are characteristic of accumulation of pseudogenes. Interestingly, a few annotated pseudogenes were indeed able to express peptides downstream of the inactivation site, suggesting the occurrence of recoding. Two mechanisms of recoding, namely, programmed frameshifting and codon redefinition, were both found. We believe that the phenomena of recoding are not rare in bacteria. More studies are required for a better understanding of bacterial translation and the implication of pseudogene recoding in Salmonella serovars.翻译重编码（Recoding）指通过非标准读取规则对mRNA翻译过程进行重编程的现象。本研究采用细胞培养氨基酸稳定同位素标记（SILAC）技术，对具有假基因（pseudogenes）富集特征的宿主适应性沙门氏菌血清型的蛋白质组展开了探究。值得注意的是，少量已注释的假基因确实能够表达其失活位点下游的肽段，这表明翻译重编码现象的发生。本研究同时发现了两种翻译重编码机制，即程序性移码（programmed frameshifting）与密码子重定义（codon redefinition）。我们认为，翻译重编码现象在细菌中并非罕见，未来仍需开展更多研究，以更深入地理解细菌翻译机制，以及沙门氏菌血清型中假基因翻译重编码的潜在意义。