Faculty, Staff and Student Publications

Language

English

Publication Date

5-1-2023

Journal

Nature Structural & Molecular Biology

DOI

10.1038/s41594-023-00974-0

PMID

37055497

PMCID

PMC10465182

PubMedCentral® Posted Date

8-29-2023

PubMedCentral® Full Text Version

Author MSS

Abstract

The insulin receptor (IR) family is a subfamily of receptor tyrosine kinases that controls metabolic homeostasis and cell growth. Distinct from IR and insulin-like growth factor 1 receptor, whose activation requires ligand binding, insulin receptor-related receptor (IRR)-the third member of the IR family-is activated by alkaline pH. However, the molecular mechanism underlying alkaline pH-induced IRR activation remains unclear. Here, we present cryo-EM structures of human IRR in both neutral pH inactive and alkaline pH active states. Combined with mutagenesis and cellular assays, we show that, upon pH increase, electrostatic repulsion of the pH-sensitive motifs of IRR disrupts its autoinhibited state and promotes a scissor-like rotation between two protomers, leading to a T-shaped active conformation. Together, our study reveals an unprecedented alkaline pH-dependent activation mechanism of IRR, opening up opportunities to understand the structure-function relationship of this important receptor.

Keywords

Humans, Receptor, Insulin, Hydrogen-Ion Concentration, Insulin

Published Open-Access

yes

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