Fr, 28.8.2026 | Original article from: MBU
A study in Nucleic Acids Research shows that short start–stop elements act as highly effective translation gates, helping control protein synthesis even under cellular stress.Unassuming Start–Stop “Gates” Regulate Protein Production in Cells
MBU: Unassuming Start–Stop “Gates” Regulate Protein Production in Cells
A new study published in Nucleic Acids Research identifies short “start–stop” elements as highly effective regulators of protein synthesis in human cells. The study was co-led by Leoš Shivaya Valášek from IMIC CAS.
MBU: Unassuming Start–Stop “Gates” Regulate Protein Production in Cells
An international team of scientists has described a previously overlooked mechanism that regulates the levels of important proteins in human cells. A new study published in Nucleic Acids Research reveals that short regulatory “start–stop“ elements act as highly effective speed-limiting gates of protein synthesis. Compared with previously known regulatory sequences, these elements were found to suppress protein production even more efficiently. At the same time, they help maintain low but stable levels of important proteins in cells, even under stress conditions. The study brought together scientists from the United States, the Czech Republic, Canada, and Sweden. Leoš Shivaya Valášek, Head of the Laboratory of Regulation of Gene Expression at the Institute of Microbiology of the Czech Academy of Sciences (IMIC CAS) was a co-author and one of the corresponding authors of the study.
During protein production, ribosomes read and translate information encoded in messenger RNA (mRNA) into amino acids, which are then assembled into a new protein. The researchers focused on an unusual sequence in which a start signal is immediately followed by a stop signal. As a result, the ribosome receives instructions to begin and terminate translation almost simultaneously. Although such an arrangement may appear illogical, it proved to be an important regulatory tool.
Start–stop motifs are found in more than 1,400 human genes and are particularly common in genes that control cellular signaling pathways, the stress response, or the activity of transcription factors—that is, proteins that regulate the activity of other genes. These genes must be tightly controlled because even small changes in the amount of their protein products can have significant biological consequences.
Resilience Under Stress
The researchers tested the activity of this regulatory mechanism under stress conditions, including in the ATF4 gene, which plays a key role in the so-called integrated stress response. Cellular stress is typically associated with a global reduction in protein synthesis. The authors demonstrated that regulation mediated by start-stop elements is largely independent of the overall state of translation initiation and therefore remains effective even under cellular stress.
A Stronger Brake Than Known Regulatory Elements
The team compared start–stop sequences with similar regulatory regions known as uTranslons. Although both types of elements suppress protein synthesis, the start–stop sequences proved to be significantly more effective. Ribosomes remain associated with these motives for longer before proceeding to the main coding region of the gene.
“Start-stop sequences are specialized regulatory elements that ensure increased ribosome retention, thereby allowing for fine-tuning translation,” says Leoš Valášek from IMIC CAS.
The study expands our understanding of how cells fine-tune protein synthesis and may ultimately contribute to research on certain cancer and neurodegenerative disorders, and other diseases linked to disrupted protein production.
The original article
Elongationless start–stop elements are stress-resilient translation gates that are more repressive than uTranslons
Justin Rendleman, Solomon A Haizel, Shaohuan Wu, Laurelle Lee Young, Junjie Liu, Xinyi Ge, Huijing Zou, Mahabub Pasha Mohammad, Matthew Pressler, Shuvadeep Maity, Vladislava Hronová, Zhaofeng Gao, Anna Hermannová, Anna Smirnova, Amy Lei, Kristina Allgoewer, Daniel Sultanov, Will Edward Hinckley, Ziyue Cheng, Lauren Shelby, Tanubrata Dey, Krzysztof J Szkop, Ivan Topisirovic, Ola Larsson, Maria Hatzoglou, Leoš Shivaya Valášek, Christine Vogel
Nucleic Acids Research (2026), Volume 54, Issue 13
https://doi.org/10.1093/nar/gkag627
licenced under CC-BY 4.0
Abstract
Start–stop elements are translation regulatory elements in 5′ untranslated regions (UTR) of eukaryotic transcripts, consisting of a start codon immediately followed by a stop codon. In contrast to canonical upstream Translons (uTranslons), they exclude elongation which creates unique properties. We conducted a comprehensive, carefully controlled comparison of human start–stop elements and uTranslons both at a genome-wide level and with targeted reporter assays. We found that start–stops and uTranslons were similar with respect to their presence in the 5′ UTRs of hundreds of genes, in particular transcription factors and signaling molecules, the low transcript levels of the corresponding genes, short RNA half-lives, and the negative effect on downstream translation. However, start–stop containing genes were translationally even more repressed than genes with uTranslons. Analysing the start–stop architecture and diverse ribosome footprinting datasets, we found evidence for a start–stop-specific mechanism that involves repeat cycling between initiation, termination, ribosome splitting, and 60S rejoining—a process possibly modulated by ASCC3 and eIF1. This cycling explained increased ribosome retention at start–stops and was—in contrast to ribosome retention at uTranslons—independent of the global initiation state. Finally, we showed that the start–stop element in human ATF4 augments the core regulatory model by controlling translation of the uTranslons.
