A previously unknown protein, hidden in RNA thought not to encode proteins, helps cells divide correctly. The RNA molecule that encodes the protein also has a function of its own in cell division. The findings from the University of Gothenburg could provide new insights into what goes wrong in conditions such as cancer.
Modern technologies have made it possible to uncover a growing “hidden proteome,” meaning proteins encoded by parts of the genome that researchers previously overlooked. Advances in sequencing and protein analysis are making it possible to find more of these potential proteins and investigate what they actually do.
Researchers at the University of Gothenburg have now identified one such protein.
An unexpected discovery
The researchers named the protein MSEP and found that it is encoded by an RNA molecule called ARHGEF17-AS1, even though this RNA had previously been classified as non-protein-coding. Both the RNA molecule and MSEP help maintain the cellular machinery that pulls chromosomes apart when a cell divides.Sagar Mahale is a researcher at Sahlgrenska Academy at the University of Gothenburg and first author of both studies:
“What is particularly interesting is that the RNA molecule and the protein do not perform the same job. They act through different pathways in the cell, but both help maintain the same essential structure when the cell divides,” he says.
In the two studies, published in the journal Cell Reports, the researchers targeted the RNA molecule and MSEP production separately in cultured cells, allowing them to distinguish between their functions.
Relevance to cancer research
Because cancer cells depend on successful cell division to proliferate, the researchers also studied the RNA molecule and MSEP in cancer cells. MSEP levels were higher in the cancer cell lines examined than in normal cell lines. When the researchers reduced the amount of RNA or disrupted MSEP production in cultured cervical cancer cells, the cells showed reduced growth and proliferation.
Chandrasekhar Kanduri is a professor at Sahlgrenska Academy at the University of Gothenburg and senior author of both studies:
“These findings raise the question of whether certain tumors are particularly dependent on MSEP to continue dividing. But it is too early to say whether the protein could become a target for future treatments,” he says.
The findings are based on studies of cultured cells. Further research is needed to determine the roles of the RNA molecule and MSEP in tumors and other tissues.
Studies:
The spindle-associated antisense RNA ARHGEF17-AS1 functionally contributes to mitotic spindle integrity; https://doi.org/10.1016/j.celrep.2026.118023 (September 22nd)
A bifunctional ARHGEF17-AS1 locus encodes MSEP, a protein that supports mitotic spindle organization; https://doi.org/10.1016/j.celrep.2026.118026 (September 24th)
Cell Reports
Experimental study
Human tissue samples
A bifunctional ARHGEF17-AS1 locus encodes MSEP, a protein that supports mitotic spindle organization
24-Sep-2026