Repository logo
 

Infancy-onset diabetes caused by de-regulated AMPylation of the human endoplasmic reticulum chaperone BiP.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Hattersley, Andrew T  ORCID logo  https://orcid.org/0000-0001-5620-473X
Wakeling, Matthew N 
Flanagan, Sarah E 

Abstract

Dysfunction of the endoplasmic reticulum (ER) in insulin-producing beta cells results in cell loss and diabetes mellitus. Here we report on five individuals from three different consanguineous families with infancy-onset diabetes mellitus and severe neurodevelopmental delay caused by a homozygous p.(Arg371Ser) mutation in FICD. The FICD gene encodes a bifunctional Fic domain-containing enzyme that regulates the ER Hsp70 chaperone, BiP, via catalysis of two antagonistic reactions: inhibitory AMPylation and stimulatory deAMPylation of BiP. Arg371 is a conserved residue in the Fic domain active site. The FICDR371S mutation partially compromises BiP AMPylation in vitro but eliminates all detectable deAMPylation activity. Overexpression of FICDR371S or knock-in of the mutation at the FICD locus of stressed CHO cells results in inappropriately elevated levels of AMPylated BiP and compromised secretion. These findings, guided by human genetics, highlight the destructive consequences of de-regulated BiP AMPylation and raise the prospect of tuning FICD's antagonistic activities towards therapeutic ends.

Description

Keywords

diabetes mellitus, endoplasmic reticulum chaperone, mutation, nucleotidyltransferases, post-translational, Animals, Cricetinae, Humans, Infant, Endoplasmic Reticulum Chaperone BiP, Protein Processing, Post-Translational, Cricetulus, Adenosine Monophosphate, Diabetes Mellitus

Journal Title

EMBO Mol Med

Conference Name

Journal ISSN

1757-4676
1757-4684

Volume Title

Publisher

Wiley
Sponsorship
Wellcome Trust (224407/Z/21/Z)
Supported by a Wellcome Trust Principal Research Fellowship to D.R. (Wellcome 200848/Z/16/Z). A Diabetes UK RD Lawrence fellowship to E.D.F. (Grant number 19_0005971), and a Wellcome Trust Senior Research Fellowship to S.E.F. (105636/Z/14/Z). M.N.W. is in receipt of an Independent Fellowship from the Exeter Diabetes Centre of Excellence funded by Research England’s Expanding Excellence in England (E3) fund