| Year | Finding/Development | Evidence type (primary/review) | Reference (journal) with DOI URL |
|---|---|---|---|
| 1992 | YDJ1/MAS5 was established as a cytosolic DnaJ/Hsp40 co-chaperone required for efficient polypeptide translocation across mitochondrial and ER membranes; C-terminal farnesylation was linked to function at elevated temperature (pqac-00000000, pqac-00000007) | Primary | Caplan AJ, Cyr DM, Douglas MG. *Cell* (1992). https://doi.org/10.1016/S0092-8674(05)80063-7 |
| 2016 | Ydj1 was shown to follow a shunt CaaX-processing pathway: it is farnesylated but typically avoids proteolysis and carboxylmethylation; forcing downstream processing perturbs localization and thermotolerance phenotypes (pqac-00000009, pqac-00000010, pqac-00000012, pqac-00000013) | Primary | Hildebrandt ER et al. *eLife* (2016). https://doi.org/10.7554/eLife.15899 |
| 2018 | Cytosolic Hsp70/Hsp40 chaperones including Ydj1 were shown to interact with newly synthesized mitochondrial beta-barrel precursors and support their import/biogenesis, placing Ydj1 upstream of TOM/Tom70-dependent pathways (pqac-00000015) | Primary | Jores T et al. *Journal of Cell Biology* (2018). https://doi.org/10.1083/jcb.201712029 |
| 2018 | Ydj1 was identified as an Hsp70 co-chaperone regulating ribonucleotide reductase stability and activity, extending its known roles from proteostasis and import to an enzyme-maturation function (pqac-00000001) | Primary | Sluder IT et al. *PLOS Genetics* (2018). https://doi.org/10.1371/journal.pgen.1007462 |
| 2020 | Expert synthesis highlighted Ydj1 as the most abundant yeast DnaJ homolog, farnesylated and localized to cytosol, ER, and mitochondrial membranes, with roles in mitochondrial and ER precursor targeting/biogenesis (pqac-00000008) | Review | Bykov YS et al. *Trends in Biochemical Sciences* (2020). https://doi.org/10.1016/j.tibs.2020.04.001 |
| 2022 | Review-level analysis emphasized that Hsp40/J-proteins are central determinants of yeast prion seed fate and proteostasis; Ydj1 was discussed as supporting fibril fragmentation but with different aggregate interactions from Sis1 (pqac-00000037, pqac-00000038, pqac-00000039) | Review | Barbitoff YA et al. *Journal of Fungi* (2022). https://doi.org/10.3390/jof8020122 |
| 2022 | Review of J-domain proteins in membrane-protein quality control highlighted Ydj1 as a farnesylation-anchored J-protein and framed JDPs as relays guiding proteins through folding, trafficking, and degradation pathways (pqac-00000036) | Review | Sagarika P et al. *Frontiers in Molecular Biosciences* (2022). https://doi.org/10.3389/fmolb.2022.1072242 |
| 2023 | A comprehensive in vivo screen used Ydj1 as an FTase reporter and showed broad reactivity of yeast farnesyltransferase across all 8000 possible CXXX sequences; Ydj1 CASQ was reaffirmed as a naturally farnesylated shunted motif and thermotolerance-linked reporter (pqac-00000026, pqac-00000027, pqac-00000028) | Primary | Kim JH et al. *G3: Genes, Genomes, Genetics* (2023). https://doi.org/10.1093/g3journal/jkad094 |
| 2023 | A yeast study concluded that Ydj1 and Mdj1 are not critically involved in Fe/S protein biogenesis or iron regulation, refining the boundaries of Ydj1 functional annotation (pqac-00000008) | Primary | Carvalho FA et al. *FEBS Letters* (2023). https://doi.org/10.1002/1873-3468.14612 |
| 2024 | A mini-review synthesized emerging knowledge on post-translational modifications of Ydj1 and DNAJA1, arguing PTMs are likely important regulators of cochaperone function and substrate handling (pqac-00000035) | Review | Mitchem MM et al. *Cell Stress and Chaperones* (2024). https://doi.org/10.1016/j.cstres.2023.11.001 |
| 2024 | Primary research mapped Ydj1 domain organization in detail and showed that J-domain lysine acetylation fine-tunes proteostasis and translational fidelity; acetyl-mimic mutants disrupted Ssa1 binding, ATPase stimulation, and stress resistance, and proteomics identified 327 interactors with acetylation-sensitive remodeling (pqac-00000016, pqac-00000030, pqac-00000031, pqac-00000032, pqac-00000033) | Primary | Omkar S et al. *PLOS Genetics* (2024). https://doi.org/10.1371/journal.pgen.1011338 |
| 2024 | Ydj1 was repurposed as a GGTase-I reporter, and systematic CXXX-space analysis showed yeast GGTase-I mainly relies on a2/X determinants; in a validation set, 8 of 15 tested CXXX motifs supported robust high-temperature growth in the Ydj1 assay (pqac-00000021, pqac-00000022) | Primary | Sarkar A et al. *G3: Genes, Genomes, Genetics* (2024). https://doi.org/10.1093/g3journal/jkae121 |


*Table: This table summarizes major milestones in functional annotation of Saccharomyces cerevisiae Ydj1/Mas5, from foundational discovery to recent 2023-2024 advances. It is useful for quickly situating core functions, post-translational regulation, and current experimental uses of Ydj1 in the literature.*