Deconstruction of O-glycosylation-GalNAc-T isoforms direct distinct subsets of the O-glycoproteome

TY - JOUR

T1 - Deconstruction of O-glycosylation-GalNAc-T isoforms direct distinct subsets of the O-glycoproteome

AU - Schjoldager, Katrine T

AU - Joshi, Hiren J

AU - Kong, Yun

AU - Goth, Christoffer K

AU - King-Smith, Sarah Louise

AU - Wandall, Hans H

AU - Bennett, Eric P

AU - Vakhrushev, Sergey Y

AU - Clausen, Henrik

N1 - © 2015 The Authors.

PY - 2015/12/1

Y1 - 2015/12/1

N2 - GalNAc-type O-glycosylation is found on most proteins trafficking through the secretory pathway in metazoan cells. The O-glycoproteome is regulated by up to 20 polypeptide GalNAc-Ts and the contributions and biological functions of individual GalNAc-Ts are poorly understood. Here, we used a zinc-finger nuclease (ZFN)-directed knockout strategy to probe the contributions of the major GalNAc-Ts (GalNAc-T1 and GalNAc-T2) in liver cells and explore how the GalNAc-T repertoire quantitatively affects the O-glycoproteome. We demonstrate that the majority of the O-glycoproteome is covered by redundancy, whereas distinct subsets of substrates are modified by non-redundant functions of GalNAc-T1 and GalNAc-T2. The non-redundant O-glycoproteome subsets and specific transcriptional responses for each isoform are related to different cellular processes; for the GalNAc-T2 isoform, these support a role in lipid metabolism. The results demonstrate that GalNAc-Ts have different non-redundant glycosylation functions, which may affect distinct cellular processes. The data serves as a comprehensive resource for unique GalNAc-T substrates. Our study provides a new view of the differential regulation of the O-glycoproteome, suggesting that the plurality of GalNAc-Ts arose to regulate distinct protein functions and cellular processes.

AB - GalNAc-type O-glycosylation is found on most proteins trafficking through the secretory pathway in metazoan cells. The O-glycoproteome is regulated by up to 20 polypeptide GalNAc-Ts and the contributions and biological functions of individual GalNAc-Ts are poorly understood. Here, we used a zinc-finger nuclease (ZFN)-directed knockout strategy to probe the contributions of the major GalNAc-Ts (GalNAc-T1 and GalNAc-T2) in liver cells and explore how the GalNAc-T repertoire quantitatively affects the O-glycoproteome. We demonstrate that the majority of the O-glycoproteome is covered by redundancy, whereas distinct subsets of substrates are modified by non-redundant functions of GalNAc-T1 and GalNAc-T2. The non-redundant O-glycoproteome subsets and specific transcriptional responses for each isoform are related to different cellular processes; for the GalNAc-T2 isoform, these support a role in lipid metabolism. The results demonstrate that GalNAc-Ts have different non-redundant glycosylation functions, which may affect distinct cellular processes. The data serves as a comprehensive resource for unique GalNAc-T substrates. Our study provides a new view of the differential regulation of the O-glycoproteome, suggesting that the plurality of GalNAc-Ts arose to regulate distinct protein functions and cellular processes.

U2 - 10.15252/embr.201540796

DO - 10.15252/embr.201540796

M3 - Journal article

C2 - 26566661

SN - 1469-221X

VL - 16

SP - 1713

EP - 1722

JO - E M B O Reports

JF - E M B O Reports

IS - 12

ER -