RT Journal Article
SR Electronic
T1 The GalNAc-T Activation (GALA) Pathway: Drivers and Markers
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 301978
DO 10.1101/301978
A1 Joanne Chia
A1 Felicia Tay
A1 Frederic Bard
YR 2018
UL http://biorxiv.org/content/early/2018/08/06/301978.abstract
AB The enzymes GALNTs add GalNAc sugar to Ser and Thr residues, forming the Tn glycan. GALNTs are activated by trafficking from Golgi to ER, a process driven by the Src kinase and negatively regulated by ERK8. This GALNTs activation (aka GALA) pathway induces high Tn levels and is a key driver of liver tumor growth. Recently, Tabak and colleagues have contested our previous data that EGF stimulation can induce GALNTs relocation. Here, we show that relocation induced by EGF is actually detectable in the images acquired by Tabak et al. Furthermore, we show that expression of EGFR enhances relocation and appears required to drive relocation induced by ERK8 depletion. We also propose that quantification of O-glycosylation of the ER resident protein PDIA4 provides an alternative measure of GALA. In sum, we demonstrate that non-reproducibility was due to experimental errors, that EGFR is indeed a driver of GALA and propose additional markers to facilitate the study of this pathway.