Native and polyubiquitinated forms of dihydroceramide desaturase are differentially linked to human embryonic kidney cell survival

Mariam Alsanafi, Samuel L. Kelly, Karawan Jubair, Melissa McNaughton, Rothwelle J. Tate, Alfred H. Merrill Jr., Susan Pyne, Nigel J Pyne

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Abstract

There is controversy concerning the role of dihydroceramide desaturase (Degs1) in regulating cell survival with studies showing that it can both promote and protect against apoptosis. We have therefore, investigated the molecular basis for these opposing roles of Degs1. Treatment of HEK293T cells with the sphingosine kinase inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) or fenretinide, but not the Degs1 inhibitor, GT11 (((N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octan-amide)) induced the polyubiquitination of Degs1 (Mr=40-140 kDa) via a mechanism involving oxidative stress, p38 MAPK and Mdm2 (E3 ligase). The polyubiquitinated forms of Degs1 exhibit ‘gain of function’ and activate pro-survival pathways, p38 MAPK, JNK and X-box protein-1s (XBP-1s). In contrast, another sphingosine kinase inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) at concentrations of 25-50 uM failed to induce formation of the polyubiquitinated forms of Degs1. In contrast with SKi, ABC294640 (25 uM) promotes apoptosis of HEK293T cells via a Degs1-dependent mechanism that is associated with increased de novo synthesis of ceramide. These findings are the first to demonstrate that the polyubiquitination of Degs1 appears to change its function from pro-apoptotic to pro-survival. Thus, polyubiquitination of Degs1 might provide an explanation for the reported opposing functions of this enzyme on cell survival/apoptosis.
LanguageEnglish
Article numbere00222
Number of pages18
JournalMolecular and Cellular Biology
Volume38
Early online date17 Sep 2018
DOIs
Publication statusPublished - 13 Nov 2018

Fingerprint

Cell Survival
p38 Mitogen-Activated Protein Kinases
Apoptosis
Kidney
Fenretinide
Ubiquitin-Protein Ligases
Survival
Ceramides
Amides
Oxidative Stress
Enzymes
dihydroceramide desaturase
3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide
Proteins
sphingosine kinase
4-(4-(4-chloro-phenyl)thiazol-2-ylamino)phenol

Keywords

  • dihydroceramide desaturase
  • sphingosine 1-phosphate
  • ER stress
  • proteasome
  • sphingosine kinase

Cite this

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title = "Native and polyubiquitinated forms of dihydroceramide desaturase are differentially linked to human embryonic kidney cell survival",
abstract = "There is controversy concerning the role of dihydroceramide desaturase (Degs1) in regulating cell survival with studies showing that it can both promote and protect against apoptosis. We have therefore, investigated the molecular basis for these opposing roles of Degs1. Treatment of HEK293T cells with the sphingosine kinase inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) or fenretinide, but not the Degs1 inhibitor, GT11 (((N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octan-amide)) induced the polyubiquitination of Degs1 (Mr=40-140 kDa) via a mechanism involving oxidative stress, p38 MAPK and Mdm2 (E3 ligase). The polyubiquitinated forms of Degs1 exhibit ‘gain of function’ and activate pro-survival pathways, p38 MAPK, JNK and X-box protein-1s (XBP-1s). In contrast, another sphingosine kinase inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) at concentrations of 25-50 uM failed to induce formation of the polyubiquitinated forms of Degs1. In contrast with SKi, ABC294640 (25 uM) promotes apoptosis of HEK293T cells via a Degs1-dependent mechanism that is associated with increased de novo synthesis of ceramide. These findings are the first to demonstrate that the polyubiquitination of Degs1 appears to change its function from pro-apoptotic to pro-survival. Thus, polyubiquitination of Degs1 might provide an explanation for the reported opposing functions of this enzyme on cell survival/apoptosis.",
keywords = "dihydroceramide desaturase, sphingosine 1-phosphate, ER stress, proteasome, sphingosine kinase",
author = "Mariam Alsanafi and Kelly, {Samuel L.} and Karawan Jubair and Melissa McNaughton and Tate, {Rothwelle J.} and {Merrill Jr.}, {Alfred H.} and Susan Pyne and Pyne, {Nigel J}",
year = "2018",
month = "11",
day = "13",
doi = "10.1128/MCB.00222-18",
language = "English",
volume = "38",
journal = "Molecular and Cellular Biology",
issn = "0270-7306",

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T1 - Native and polyubiquitinated forms of dihydroceramide desaturase are differentially linked to human embryonic kidney cell survival

AU - Alsanafi, Mariam

AU - Kelly, Samuel L.

AU - Jubair, Karawan

AU - McNaughton, Melissa

AU - Tate, Rothwelle J.

AU - Merrill Jr., Alfred H.

AU - Pyne, Susan

AU - Pyne, Nigel J

PY - 2018/11/13

Y1 - 2018/11/13

N2 - There is controversy concerning the role of dihydroceramide desaturase (Degs1) in regulating cell survival with studies showing that it can both promote and protect against apoptosis. We have therefore, investigated the molecular basis for these opposing roles of Degs1. Treatment of HEK293T cells with the sphingosine kinase inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) or fenretinide, but not the Degs1 inhibitor, GT11 (((N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octan-amide)) induced the polyubiquitination of Degs1 (Mr=40-140 kDa) via a mechanism involving oxidative stress, p38 MAPK and Mdm2 (E3 ligase). The polyubiquitinated forms of Degs1 exhibit ‘gain of function’ and activate pro-survival pathways, p38 MAPK, JNK and X-box protein-1s (XBP-1s). In contrast, another sphingosine kinase inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) at concentrations of 25-50 uM failed to induce formation of the polyubiquitinated forms of Degs1. In contrast with SKi, ABC294640 (25 uM) promotes apoptosis of HEK293T cells via a Degs1-dependent mechanism that is associated with increased de novo synthesis of ceramide. These findings are the first to demonstrate that the polyubiquitination of Degs1 appears to change its function from pro-apoptotic to pro-survival. Thus, polyubiquitination of Degs1 might provide an explanation for the reported opposing functions of this enzyme on cell survival/apoptosis.

AB - There is controversy concerning the role of dihydroceramide desaturase (Degs1) in regulating cell survival with studies showing that it can both promote and protect against apoptosis. We have therefore, investigated the molecular basis for these opposing roles of Degs1. Treatment of HEK293T cells with the sphingosine kinase inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) or fenretinide, but not the Degs1 inhibitor, GT11 (((N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octan-amide)) induced the polyubiquitination of Degs1 (Mr=40-140 kDa) via a mechanism involving oxidative stress, p38 MAPK and Mdm2 (E3 ligase). The polyubiquitinated forms of Degs1 exhibit ‘gain of function’ and activate pro-survival pathways, p38 MAPK, JNK and X-box protein-1s (XBP-1s). In contrast, another sphingosine kinase inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) at concentrations of 25-50 uM failed to induce formation of the polyubiquitinated forms of Degs1. In contrast with SKi, ABC294640 (25 uM) promotes apoptosis of HEK293T cells via a Degs1-dependent mechanism that is associated with increased de novo synthesis of ceramide. These findings are the first to demonstrate that the polyubiquitination of Degs1 appears to change its function from pro-apoptotic to pro-survival. Thus, polyubiquitination of Degs1 might provide an explanation for the reported opposing functions of this enzyme on cell survival/apoptosis.

KW - dihydroceramide desaturase

KW - sphingosine 1-phosphate

KW - ER stress

KW - proteasome

KW - sphingosine kinase

UR - https://mcb.asm.org/

U2 - 10.1128/MCB.00222-18

DO - 10.1128/MCB.00222-18

M3 - Article

VL - 38

JO - Molecular and Cellular Biology

T2 - Molecular and Cellular Biology

JF - Molecular and Cellular Biology

SN - 0270-7306

M1 - e00222

ER -