Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain

Dong hyun Hong, Jianya Huan, Bor rung Ou, Jan ying Yeh, Takaomi C. Saido, P. R. Cheeke, Neil E. Forsberg

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

Objectives were to identify the PKC isoforms in cultured muscle cells, to examine roles of Ca 2+-dependent proteinases (calpains) in processing of various muscle PKC isozymes and to obtain a mechanistic description of the processing of PKCs by examining the temporal relationships between phorbol ester-dependent translocation of muscle PKCs and calpains between cytosolic and membrane compartments. Using six isoform (α, β, γ, σ, ε{lunate}, ζ )-specific polyclonal antibodies, PKC α, σ and ζ were detected in rat skeletal muscle and in L8 myoblasts and myotubes. PKC α and ζ were primarily localized in the cytosolic fraction of L8 myotubes whereas PKC σ was more abundant in the membrane fraction. Phorbol ester (TPA) caused rapid depletion of myotube PKC α and PKC σ isoforms from the cytosolic compartment and rapid appearance of these isoforms in the membrane fraction. However, long-term exposure of myotubes to TPA eventually caused down-regulation of PKCs in the membrane compartment. Down-regulation of PKCs in the membrane fraction was partially blocked by calpain inhibitor II. However, the rapid TPA-dependent cytosolic depletion of PKCs was unaffected by calpain inhibitor. This suggests that calpains may be responsible for membrane-associated down-regulation of PKCs but not for cytosolic depletion. In the final study we assessed the effects of phorbol ester on compartmentation of m-calpain with PKCs in muscle cells. Like the PKCs, TPA caused rapid association of m-calpain with the membrane fraction followed by down-regulation. This demonstrates that phorbol esters cause translocation of both PKCs and calpains to membranes where processing of PKCs may occur via the limited proteolysis exerted by calpains.

Original languageEnglish (US)
Pages (from-to)45-54
Number of pages10
JournalBBA - Molecular Cell Research
Volume1267
Issue number1
DOIs
StatePublished - May 29 1995
Externally publishedYes

Fingerprint

Calpain
Phorbol Esters
Muscle Cells
Protein Kinase C
Protein Isoforms
Membranes
Skeletal Muscle Fibers
Down-Regulation
Muscles
Myoblasts
Isoenzymes
Proteolysis
Cultured Cells
Skeletal Muscle
Peptide Hydrolases
Antibodies

Keywords

  • Calpain
  • Muscle cell
  • Phorbol ester
  • Protein kinase C

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology
  • Biophysics

Cite this

Hong, D. H., Huan, J., Ou, B. R., Yeh, J. Y., Saido, T. C., Cheeke, P. R., & Forsberg, N. E. (1995). Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain. BBA - Molecular Cell Research, 1267(1), 45-54. https://doi.org/10.1016/0167-4889(95)00024-M

Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain. / Hong, Dong hyun; Huan, Jianya; Ou, Bor rung; Yeh, Jan ying; Saido, Takaomi C.; Cheeke, P. R.; Forsberg, Neil E.

In: BBA - Molecular Cell Research, Vol. 1267, No. 1, 29.05.1995, p. 45-54.

Research output: Contribution to journalArticle

Hong, DH, Huan, J, Ou, BR, Yeh, JY, Saido, TC, Cheeke, PR & Forsberg, NE 1995, 'Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain', BBA - Molecular Cell Research, vol. 1267, no. 1, pp. 45-54. https://doi.org/10.1016/0167-4889(95)00024-M
Hong, Dong hyun ; Huan, Jianya ; Ou, Bor rung ; Yeh, Jan ying ; Saido, Takaomi C. ; Cheeke, P. R. ; Forsberg, Neil E. / Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain. In: BBA - Molecular Cell Research. 1995 ; Vol. 1267, No. 1. pp. 45-54.
@article{2b017378beaa4295b526759ed79d8805,
title = "Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain",
abstract = "Objectives were to identify the PKC isoforms in cultured muscle cells, to examine roles of Ca 2+-dependent proteinases (calpains) in processing of various muscle PKC isozymes and to obtain a mechanistic description of the processing of PKCs by examining the temporal relationships between phorbol ester-dependent translocation of muscle PKCs and calpains between cytosolic and membrane compartments. Using six isoform (α, β, γ, σ, ε{lunate}, ζ )-specific polyclonal antibodies, PKC α, σ and ζ were detected in rat skeletal muscle and in L8 myoblasts and myotubes. PKC α and ζ were primarily localized in the cytosolic fraction of L8 myotubes whereas PKC σ was more abundant in the membrane fraction. Phorbol ester (TPA) caused rapid depletion of myotube PKC α and PKC σ isoforms from the cytosolic compartment and rapid appearance of these isoforms in the membrane fraction. However, long-term exposure of myotubes to TPA eventually caused down-regulation of PKCs in the membrane compartment. Down-regulation of PKCs in the membrane fraction was partially blocked by calpain inhibitor II. However, the rapid TPA-dependent cytosolic depletion of PKCs was unaffected by calpain inhibitor. This suggests that calpains may be responsible for membrane-associated down-regulation of PKCs but not for cytosolic depletion. In the final study we assessed the effects of phorbol ester on compartmentation of m-calpain with PKCs in muscle cells. Like the PKCs, TPA caused rapid association of m-calpain with the membrane fraction followed by down-regulation. This demonstrates that phorbol esters cause translocation of both PKCs and calpains to membranes where processing of PKCs may occur via the limited proteolysis exerted by calpains.",
keywords = "Calpain, Muscle cell, Phorbol ester, Protein kinase C",
author = "Hong, {Dong hyun} and Jianya Huan and Ou, {Bor rung} and Yeh, {Jan ying} and Saido, {Takaomi C.} and Cheeke, {P. R.} and Forsberg, {Neil E.}",
year = "1995",
month = "5",
day = "29",
doi = "10.1016/0167-4889(95)00024-M",
language = "English (US)",
volume = "1267",
pages = "45--54",
journal = "Biochimica et Biophysica Acta - Molecular Cell Research",
issn = "0167-4889",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain

AU - Hong, Dong hyun

AU - Huan, Jianya

AU - Ou, Bor rung

AU - Yeh, Jan ying

AU - Saido, Takaomi C.

AU - Cheeke, P. R.

AU - Forsberg, Neil E.

PY - 1995/5/29

Y1 - 1995/5/29

N2 - Objectives were to identify the PKC isoforms in cultured muscle cells, to examine roles of Ca 2+-dependent proteinases (calpains) in processing of various muscle PKC isozymes and to obtain a mechanistic description of the processing of PKCs by examining the temporal relationships between phorbol ester-dependent translocation of muscle PKCs and calpains between cytosolic and membrane compartments. Using six isoform (α, β, γ, σ, ε{lunate}, ζ )-specific polyclonal antibodies, PKC α, σ and ζ were detected in rat skeletal muscle and in L8 myoblasts and myotubes. PKC α and ζ were primarily localized in the cytosolic fraction of L8 myotubes whereas PKC σ was more abundant in the membrane fraction. Phorbol ester (TPA) caused rapid depletion of myotube PKC α and PKC σ isoforms from the cytosolic compartment and rapid appearance of these isoforms in the membrane fraction. However, long-term exposure of myotubes to TPA eventually caused down-regulation of PKCs in the membrane compartment. Down-regulation of PKCs in the membrane fraction was partially blocked by calpain inhibitor II. However, the rapid TPA-dependent cytosolic depletion of PKCs was unaffected by calpain inhibitor. This suggests that calpains may be responsible for membrane-associated down-regulation of PKCs but not for cytosolic depletion. In the final study we assessed the effects of phorbol ester on compartmentation of m-calpain with PKCs in muscle cells. Like the PKCs, TPA caused rapid association of m-calpain with the membrane fraction followed by down-regulation. This demonstrates that phorbol esters cause translocation of both PKCs and calpains to membranes where processing of PKCs may occur via the limited proteolysis exerted by calpains.

AB - Objectives were to identify the PKC isoforms in cultured muscle cells, to examine roles of Ca 2+-dependent proteinases (calpains) in processing of various muscle PKC isozymes and to obtain a mechanistic description of the processing of PKCs by examining the temporal relationships between phorbol ester-dependent translocation of muscle PKCs and calpains between cytosolic and membrane compartments. Using six isoform (α, β, γ, σ, ε{lunate}, ζ )-specific polyclonal antibodies, PKC α, σ and ζ were detected in rat skeletal muscle and in L8 myoblasts and myotubes. PKC α and ζ were primarily localized in the cytosolic fraction of L8 myotubes whereas PKC σ was more abundant in the membrane fraction. Phorbol ester (TPA) caused rapid depletion of myotube PKC α and PKC σ isoforms from the cytosolic compartment and rapid appearance of these isoforms in the membrane fraction. However, long-term exposure of myotubes to TPA eventually caused down-regulation of PKCs in the membrane compartment. Down-regulation of PKCs in the membrane fraction was partially blocked by calpain inhibitor II. However, the rapid TPA-dependent cytosolic depletion of PKCs was unaffected by calpain inhibitor. This suggests that calpains may be responsible for membrane-associated down-regulation of PKCs but not for cytosolic depletion. In the final study we assessed the effects of phorbol ester on compartmentation of m-calpain with PKCs in muscle cells. Like the PKCs, TPA caused rapid association of m-calpain with the membrane fraction followed by down-regulation. This demonstrates that phorbol esters cause translocation of both PKCs and calpains to membranes where processing of PKCs may occur via the limited proteolysis exerted by calpains.

KW - Calpain

KW - Muscle cell

KW - Phorbol ester

KW - Protein kinase C

UR - http://www.scopus.com/inward/record.url?scp=0029019655&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029019655&partnerID=8YFLogxK

U2 - 10.1016/0167-4889(95)00024-M

DO - 10.1016/0167-4889(95)00024-M

M3 - Article

C2 - 7779868

AN - SCOPUS:0029019655

VL - 1267

SP - 45

EP - 54

JO - Biochimica et Biophysica Acta - Molecular Cell Research

JF - Biochimica et Biophysica Acta - Molecular Cell Research

SN - 0167-4889

IS - 1

ER -