Fig. 5.

Glycogene analysis in HEK^XBP1s and HeLa^XBP1s cells. (A) Volcano plot showing XBP1s activation-induced changes in glycosylation-related transcripts in HEK^XBP1s cells. Glycogenes analyzed are listed in Dataset S5B. Data shown were obtained either from the Qiagen Human Glycosylation qPCR Array or, if a transcript of interest was not included in the qPCR array, extracted from previously published HEK^XBP1s microarray data (4). Transcripts shown in teal meet significance and fold-change thresholds of FDR or P value ≤0.05 and fold change ≥1.5 upon XBP1s activation. Gene symbols are shown for outliers and transcripts of particular interest. (B) Decreased expression of MGAT3 (shown in pink in A), a GlcNAc transferase (36), could account for the loss in bisecting GlcNAc observed on HEK^XBP1s secreted and membrane glycoproteins upon XBP1s activation. Decreased expression of ST6GAL1 and increased expression of NEU1 could account for the reduced sialylation observed for HEK^XBP1s secreted and membrane glycoproteins upon XBP1s activation. (C) Volcano plot showing XBP1s activation-induced changes in glycosylation-related transcripts in HeLa^XBP1s cells. Glycogenes analyzed are listed in Dataset S5B. Data shown were obtained either from the Qiagen Human Glycosylation qPCR Array or, if a transcript of interest was not included in the qPCR array, extracted from the RNA-seq data. Transcripts shown in blue meet significance and fold-change thresholds of FDR or P value ≤0.05 and fold change ≥1.5 upon XBP1s activation. Gene symbols are shown for outliers and transcripts of particular interest. (D) Increased expression of GFPT1, PGM3, SLC35A3, or UAP1, which are enzymes involved in regulating UDP-GlcNAc availability (shown in orange in C), could contribute to increased tetraantennary N-glycans observed on HeLa^XBP1s membranes upon XBP1s activation.