ArticleProtein science : a publication of the Protein Society2026
Mechanism-guided mutagenesis of Rft1 to test its role as a dolichol-linked oligosaccharide scramblase in cells.
Article in Protein science : a publication of the Protein Society, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
- Update of
Authors and funding
5 authors.
Funding
Abstract
The membrane protein Rft1 is proposed to play an essential role in yeast and human cells by scrambling the glycolipid Man5GlcNAc2-PP-dolichol (M5-DLO) across the endoplasmic reticulum (ER) for protein N-glycosylation. While this activity has been demonstrated in liposomes reconstituted with purified Rft1, biochemical evidence of additional M5-DLO scramblases and the viability of Rft1-null Trypanosoma brucei suggest that scrambling may be a moonlighting function of Rft1 rather than its essential cellular role. To investigate this problem, we used AlphaFold3 and Chai-1 to model the conformational dynamics of yeast Rft1-M5-DLO complexes. The models suggest an alternating access mechanism, typical of Multidrug/Oligosaccharidyl-lipid/Polysaccharide (MOP) superfamily transporters, in which a cationic central cavity coordinates the anionic headgroup of M5-DLO, while the dolichol tail of the lipid is accommodated through a lateral portal formed by two transmembrane helices. We used the models to design mutations to disrupt the interaction between Rft1 and the M5-DLO headgroup, and to engineer a salt bridge to block the portal and stall transport. Using a Tet-off yeast reporter strain, we tested 26 central cavity mutants and identified 2 that supported cell growth poorly despite being well-expressed. Strikingly, the portal-blocking mutant which is predicted to lack scramblase activity supported robust growth. These data suggest that while M5-DLO binding is important for Rft1's essential function, scrambling activity is dispensable. We speculate that Rft1's essential role may be as an M5-DLO chaperone, capturing and routing M5-DLO propitiously on the cytoplasmic side of the ER to coordinate DLO biosynthesis.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.