Hydrophobicity of protein determinants influences the recognition of substrates by EDEM1 and EDEM2 in human cellsReport as inadecuate




Hydrophobicity of protein determinants influences the recognition of substrates by EDEM1 and EDEM2 in human cells - Download this document for free, or read online. Document in PDF available to download.

BMC Cell Biology

, 16:1

First Online: 06 February 2015Received: 14 August 2014Accepted: 05 January 2015DOI: 10.1186-s12860-015-0047-7

Cite this article as: Sokołowska, I., Piłka, E.S., Sandvig, K. et al. BMC Cell Biol 2015 16: 1. doi:10.1186-s12860-015-0047-7

Abstract

BackgroundEDEM1 and EDEM2 are crucial regulators of the endoplasmic reticulum ER-associated degradation ERAD that extracts misfolded glycoproteins from the calnexin chaperone system. The degradation of ERAD substrates involves mannose trimming of N-linked glycans; however the precise mechanism of substrate recognition and sorting to the ERAD pathway is still poorly understood. It has previously been demonstrated that EDEM1 and EDEM2 binding does not require the trimming of substrate glycans or even ERAD substrate glycosylation, thus suggesting that both chaperones probably recognize misfolded regions of aberrant proteins.

ResultsIn this work, we focused on the substrate recognition by EDEM1 and EDEM2, asking whether hydrophobicity of protein determinants might be important for these interactions in human cells. In the study we used ricin, a protein toxin that utilizes the ERAD pathway in its retrotranslocation from the ER to the cytosol, and a model misfolded protein, the pancreatic isoform of human β-secretase, BACE457. Mutations in the hydrophobic regions of these proteins allowed us to obtain mutated forms with increased and decreased hydrophobicity.

ConclusionsOur data provide the first evidence that recognition of ERAD substrates by EDEM1 and EDEM2 might be determined by a sufficiently high hydrophobicity of protein determinants. Moreover, EDEM proteins can bind hydrophobic transmembrane regions of misfolded ERAD substrates. These data contribute to the general understanding of the regulation of ERAD in mammalian cells.

KeywordsEndoplasmic reticulum ERAD EDEM proteins Ricin BACE457 AbbreviationsEREndoplasmic reticulum

RTARicin A-chain

RTBRicin B-chain

P250ASubstitution of proline 250 into alanine

RTADHFRicin A-chain with decreased hydrophobicity in the C-terminal region

RTAIHFRicin A-chain with increased hydrophobicity in the C-terminal region

EDEM1ER degradation enhancing α-mannosidase I-like protein 1

EDEM2ER degradation enhancing α-mannosidase I-like protein 2

ERADER-associated protein degradation

TCATrichloroacetic acid

CHAPS3-3-cholamidopropyldimethylammoniopropane-1-sulfonic acid, HA- hemagglutinin

Electronic supplementary materialThe online version of this article doi:10.1186-s12860-015-0047-7 contains supplementary material, which is available to authorized users.

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Author: Iwona Sokołowska - Ewa S Piłka - Kirsten Sandvig - Grzegorz Węgrzyn - Monika Słomińska-Wojewódzka

Source: https://link.springer.com/







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