N-Glycanase 1 Transcriptionally Regulates Aquaporins Independent of Its Enzymatic Activity

Cell Rep. 2019 Dec 24;29(13):4620-4631.e4. doi: 10.1016/j.celrep.2019.11.097.

Abstract

Patients with pathogenic mutations in NGLY1 cannot make tears and have global developmental delay and liver dysfunction. Traditionally, NGLY1 cleaves intact N-glycans from misfolded, retrotranslocated glycoproteins before proteasomal degradation. We demonstrate that Ngly1-null mouse embryonic fibroblasts, NGLY1 knockout human cells, and patient fibroblasts are resistant to hypotonic lysis. Ngly1-deficient mouse embryonic fibroblasts swell slower and have reduced aquaporin1 mRNA and protein expression. Ngly1 knockdown and overexpression confirms that Ngly1 regulates aquaporin1 and hypotonic cell lysis. Patient fibroblasts and NGLY1 knockout cells show reduced aquaporin11 mRNA, supporting NGLY1 as regulating expression of multiple aquaporins across species. Complementing Ngly1-deficient cells with catalytically inactive NGLY1 (p.Cys309Ala) restores normal hypotonic lysis and aquaporin1 protein. We show that transcription factors Atf1/Creb1 regulate aquaporin1 and that the Atf1/Creb1 signaling pathway is disrupted in Ngly1-deficient mouse embryonic fibroblasts. These results identify a non-enzymatic, regulatory function of NGLY1 in aquaporin transcription, possibly related to alacrima and neurological symptoms.

Keywords: Atf1/Creb1; N-glycanase 1; aquaporins; deglycosylation; hypotonic stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activating Transcription Factor 1 / genetics
  • Activating Transcription Factor 1 / metabolism
  • Animals
  • Aquaporin 1 / genetics*
  • Aquaporin 1 / metabolism
  • Aquaporins / genetics*
  • Aquaporins / metabolism
  • Cell Line
  • Congenital Disorders of Glycosylation / genetics*
  • Congenital Disorders of Glycosylation / metabolism
  • Congenital Disorders of Glycosylation / pathology
  • Eye Diseases, Hereditary / genetics*
  • Eye Diseases, Hereditary / metabolism
  • Eye Diseases, Hereditary / pathology
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Gene Expression Regulation
  • Genetic Complementation Test
  • Humans
  • Isoenzymes / antagonists & inhibitors
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Lacrimal Apparatus Diseases / genetics*
  • Lacrimal Apparatus Diseases / metabolism
  • Lacrimal Apparatus Diseases / pathology
  • Mice
  • Mice, Knockout
  • Osmosis
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / antagonists & inhibitors
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / deficiency*
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / genetics
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / metabolism
  • Polysaccharides / metabolism
  • Primary Cell Culture
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Signal Transduction
  • Transcription, Genetic*

Substances

  • AQP1 protein, human
  • AQP11 protein, human
  • ATF1 protein, human
  • Activating Transcription Factor 1
  • Aquaporins
  • Isoenzymes
  • Polysaccharides
  • RNA, Messenger
  • RNA, Small Interfering
  • Aquaporin 1
  • NGLY1 protein, human
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase

Supplementary concepts

  • Alacrima
  • NGLY1 deficiency