Tabitha Peterson maps hundreds of new Rab GTPase interactions

Congratulations to Tabitha Peterson, first author of our new paper surveying nucleotide specific interactions across the human Rab GTPase family. Tabitha screened 36 human Rab GTPases, each locked in either its GTP or GDP bound state, using DEEPN, our batch yeast two hybrid platform. These screens identified 527 Rab interactions involving 337 different proteins. Only 26 of these interactions were previously documented in BioGRID, so the large majority are new.

Two advances made this survey possible. First, we built custom yeast two hybrid libraries from the Human ORFeome and from yeast genomic DNA. Conventional cDNA libraries are dominated by 3′ untranslated sequence. Our human library instead contains about one million unique elements and nearly three times the proportion of in frame coding fragments found in a commercial library. Second, the updated DEEPN software suite (DEEPN v7, StatMaker, MAPster, and the new FragFinder module) maps every hit to the specific protein fragment that binds. This fragment level view separates genuine interactions from background and pinpoints binding domains directly from the screen.

The data show that many known Rab effectors bind a wider set of Rab partners than previously appreciated. They also identify the RGS domains of SNX13 and SNX14 as a new class of Rab binding domain that may link these ER proteins to Rab5 and Rab11 endosomal compartments.

This was a tremendous effort by Tabitha, with NMR work from Chris Ptak.

Survey of nucleotide-specific Rab GTPase interactions reveals multiple Rab effectors

Tabitha A. Peterson, Christopher P. Ptak, Robert C. Piper

bioRxiv 2026.09.15.751902; doi: https://doi.org/10.64898/2026.09.15.751902