biostudies-literatureUnknownKentache TEuropean Research CouncilNCI NIH HHSNIGMS NIH HHSGlycosylation-deficient Chinese hamster ovary (CHO) cell lines have been instrumental in the discovery of N-glycosylation machinery. Yet, the molecular causes of the glycosylation defects in the Lec5 and Lec9 mutants have been elusive, even though for both cell lines a defect in dolichol formation from polyprenol was previously established. We recently found that dolichol synthesis from polyprenol occurs in three steps consisting of the conversion of polyprenol to polyprenal by DHRSX, the reduction of polyprenal to dolichal by SRD5A3 and the reduction of dolichal to dolichol, again by DHRSX. This led us to investigate defective dolichol synthesis in Lec5 and Lec9 cells. Both cell lines showed increased levels of polyprenol and its derivatives, concomitant with decreased levels of dolichol bioRxiv : the preprint server for biology2024.06.18.599300https://www.ebi.ac.uk/biostudies/studies/S-EPMC11212957biostudies-literatureThe N-glycosylation defect in Lec5 and Lec9 CHO cells is caused by absence of the DHRSX gene.PMC11212957771704R01 GM105399R01 CA036434Contessa JNBommer GTWilson MPCaligiore FSchulz CGraff JPieters EStanley PSouche EKentache TAlthoff CRMatthijs GVan Schaftingen EFoulquier FfalseThe N-glycosylation defect in Lec5 and Lec9 CHO cells is caused by absence of the DHRSX gene.Glycosylation-deficient Chinese hamster ovary (CHO) cell lines have been instrumental in the discovery of N-glycosylation machinery. Yet, the molecular causes of the glycosylation defects in the Lec5 and Lec9 mutants have been elusive, even though for both cell lines a defect in dolichol formation from polyprenol was previously established. We recently found that dolichol synthesis from polyprenol occurs in three steps consisting of the conversion of polyprenol to polyprenal by DHRSX, the reduction of polyprenal to dolichal by SRD5A3 and the reduction of dolichal to dolichol, again by DHRSX. This led us to investigate defective dolichol synthesis in Lec5 and Lec9 cells. Both cell lines showed increased levels of polyprenol and its derivatives, concomitant with decreased levels of dolichol 2024-01-01T00:00:00Z2024 Jun2026-04-08T01:26:18.323Z2025-04-06T08:21:58.413ZS-EPMC112129573894879710.1101/2024.06.18.599300