Regulation of Bnip3 death pathways by calcium, phosphorylation, and hypoxia-reoxygenation

Regina M Graham, John W. Thompson, Jianqin Wei, Nanette Bishopric, Keith A Webster

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Bnip3 is a proapoptotic member of the Bcl-2 family of death-regulating proteins that promote the intrinsic pathway of programmed cell death. The Bnip3 death program requires membrane insertion through an N-terminal transmembrane domain that directs the protein to mitochondrial and endoplasmic reticular (ER) membranes. We have reported that simulated ischemia induces transcription of the Bnip3 gene, and Bnip3 protein is stabilized by acidosis. Bnip3 programmed death is atypical, with features of both apoptosis and necrosis. Here we demonstrate that hypoxia-reoxygenation and agents that activate protein kinase C, including calcium ionophore, phorbol 12-myristate 13-acetate, and okadaic acid, also induce Bnip3. The molecular size of Bnip3 predicted from the amino acid sequence is 21.5 kDa, but the protein typically migrates in SDS-PAGE as a 31-kDa monomer and 60-kDa dimer. Treatment of cell extracts containing Bnip3 with phosphatase yielded a series of rapidly migrating species, the smallest of which corresponded with the theoretic molecular size of Bnip3. Conversely, treatment of cells with okadaic acid eliminated the rapidly migrating species, suggesting that Bnip3 phosphorylation is a dynamic process. Elevated levels of the phosphoprotein correlated with initiation of Bnip3-dependent death, whereas the dephosphorylated species correlated with extreme acidosis.

Original languageEnglish
Pages (from-to)1309-1315
Number of pages7
JournalAntioxidants and Redox Signaling
Volume9
Issue number9
DOIs
StatePublished - Sep 1 2007

Fingerprint

Phosphorylation
Calcium
Okadaic Acid
Acidosis
Proteins
Cells
Membranes
Calcium Ionophores
Phosphoproteins
Mitochondrial Proteins
Cell death
Transcription
Cell Extracts
Phosphoric Monoester Hydrolases
Dimers
Protein Kinase C
Polyacrylamide Gel Electrophoresis
Amino Acid Sequence
Acetates
Cell Death

ASJC Scopus subject areas

  • Biochemistry

Cite this

Regulation of Bnip3 death pathways by calcium, phosphorylation, and hypoxia-reoxygenation. / Graham, Regina M; Thompson, John W.; Wei, Jianqin; Bishopric, Nanette; Webster, Keith A.

In: Antioxidants and Redox Signaling, Vol. 9, No. 9, 01.09.2007, p. 1309-1315.

Research output: Contribution to journalArticle

Graham, Regina M ; Thompson, John W. ; Wei, Jianqin ; Bishopric, Nanette ; Webster, Keith A. / Regulation of Bnip3 death pathways by calcium, phosphorylation, and hypoxia-reoxygenation. In: Antioxidants and Redox Signaling. 2007 ; Vol. 9, No. 9. pp. 1309-1315.
@article{9992dcd7ae1b47a9b437c3851f5d527c,
title = "Regulation of Bnip3 death pathways by calcium, phosphorylation, and hypoxia-reoxygenation",
abstract = "Bnip3 is a proapoptotic member of the Bcl-2 family of death-regulating proteins that promote the intrinsic pathway of programmed cell death. The Bnip3 death program requires membrane insertion through an N-terminal transmembrane domain that directs the protein to mitochondrial and endoplasmic reticular (ER) membranes. We have reported that simulated ischemia induces transcription of the Bnip3 gene, and Bnip3 protein is stabilized by acidosis. Bnip3 programmed death is atypical, with features of both apoptosis and necrosis. Here we demonstrate that hypoxia-reoxygenation and agents that activate protein kinase C, including calcium ionophore, phorbol 12-myristate 13-acetate, and okadaic acid, also induce Bnip3. The molecular size of Bnip3 predicted from the amino acid sequence is 21.5 kDa, but the protein typically migrates in SDS-PAGE as a 31-kDa monomer and 60-kDa dimer. Treatment of cell extracts containing Bnip3 with phosphatase yielded a series of rapidly migrating species, the smallest of which corresponded with the theoretic molecular size of Bnip3. Conversely, treatment of cells with okadaic acid eliminated the rapidly migrating species, suggesting that Bnip3 phosphorylation is a dynamic process. Elevated levels of the phosphoprotein correlated with initiation of Bnip3-dependent death, whereas the dephosphorylated species correlated with extreme acidosis.",
author = "Graham, {Regina M} and Thompson, {John W.} and Jianqin Wei and Nanette Bishopric and Webster, {Keith A}",
year = "2007",
month = "9",
day = "1",
doi = "10.1089/ars.2007.1726",
language = "English",
volume = "9",
pages = "1309--1315",
journal = "Antioxidants and Redox Signaling",
issn = "1523-0864",
publisher = "Mary Ann Liebert Inc.",
number = "9",

}

TY - JOUR

T1 - Regulation of Bnip3 death pathways by calcium, phosphorylation, and hypoxia-reoxygenation

AU - Graham, Regina M

AU - Thompson, John W.

AU - Wei, Jianqin

AU - Bishopric, Nanette

AU - Webster, Keith A

PY - 2007/9/1

Y1 - 2007/9/1

N2 - Bnip3 is a proapoptotic member of the Bcl-2 family of death-regulating proteins that promote the intrinsic pathway of programmed cell death. The Bnip3 death program requires membrane insertion through an N-terminal transmembrane domain that directs the protein to mitochondrial and endoplasmic reticular (ER) membranes. We have reported that simulated ischemia induces transcription of the Bnip3 gene, and Bnip3 protein is stabilized by acidosis. Bnip3 programmed death is atypical, with features of both apoptosis and necrosis. Here we demonstrate that hypoxia-reoxygenation and agents that activate protein kinase C, including calcium ionophore, phorbol 12-myristate 13-acetate, and okadaic acid, also induce Bnip3. The molecular size of Bnip3 predicted from the amino acid sequence is 21.5 kDa, but the protein typically migrates in SDS-PAGE as a 31-kDa monomer and 60-kDa dimer. Treatment of cell extracts containing Bnip3 with phosphatase yielded a series of rapidly migrating species, the smallest of which corresponded with the theoretic molecular size of Bnip3. Conversely, treatment of cells with okadaic acid eliminated the rapidly migrating species, suggesting that Bnip3 phosphorylation is a dynamic process. Elevated levels of the phosphoprotein correlated with initiation of Bnip3-dependent death, whereas the dephosphorylated species correlated with extreme acidosis.

AB - Bnip3 is a proapoptotic member of the Bcl-2 family of death-regulating proteins that promote the intrinsic pathway of programmed cell death. The Bnip3 death program requires membrane insertion through an N-terminal transmembrane domain that directs the protein to mitochondrial and endoplasmic reticular (ER) membranes. We have reported that simulated ischemia induces transcription of the Bnip3 gene, and Bnip3 protein is stabilized by acidosis. Bnip3 programmed death is atypical, with features of both apoptosis and necrosis. Here we demonstrate that hypoxia-reoxygenation and agents that activate protein kinase C, including calcium ionophore, phorbol 12-myristate 13-acetate, and okadaic acid, also induce Bnip3. The molecular size of Bnip3 predicted from the amino acid sequence is 21.5 kDa, but the protein typically migrates in SDS-PAGE as a 31-kDa monomer and 60-kDa dimer. Treatment of cell extracts containing Bnip3 with phosphatase yielded a series of rapidly migrating species, the smallest of which corresponded with the theoretic molecular size of Bnip3. Conversely, treatment of cells with okadaic acid eliminated the rapidly migrating species, suggesting that Bnip3 phosphorylation is a dynamic process. Elevated levels of the phosphoprotein correlated with initiation of Bnip3-dependent death, whereas the dephosphorylated species correlated with extreme acidosis.

UR - http://www.scopus.com/inward/record.url?scp=34547875432&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34547875432&partnerID=8YFLogxK

U2 - 10.1089/ars.2007.1726

DO - 10.1089/ars.2007.1726

M3 - Article

VL - 9

SP - 1309

EP - 1315

JO - Antioxidants and Redox Signaling

JF - Antioxidants and Redox Signaling

SN - 1523-0864

IS - 9

ER -