Altering the stability of the Cdc8 overlap region modulates the ability of this tropomyosin to bind co-operatively to actin and regulate myosin

Daniel A. East, Duncan Sousa, Stephen R. Martin, Thomas A. Edwards, William Lehman, Daniel P. Mulvihill

Research output: Contribution to journalArticle

Abstract

Tm(tropomyosin) is an evolutionarily conserved α-helical coiled-coil protein, dimers of which form end-to-end polymers capable of associating with and stabilizing actin filaments, and regulating myosin function. The fission yeast Schizosaccharomyces pombe possesses a single essential Tm, Cdc8, which can be acetylated on its N-terminal methionine residue to increase its affinity for actin and enhance its ability to regulate myosin function. We have designed and generated a number of novel Cdc8 mutant proteins with N-terminal substitutions to explore how stability of the Cdc8 overlap region affects the regulatory function of this Tm. By correlating the stability of each protein, its propensity to form stable polymers, its ability to associate with actin and to regulatemyosin,we have shownthat the stability of the N-terminal of the Cdc8 α-helix is crucial for Tm function. In addition we have identified a novel Cdc8 mutant with increased N-terminal stability, dimers of which are capable of forming Tm polymers significantly longer than the wild-type protein. This protein had a reduced affinity for actin with respect to wild-type, andwas unable to regulate actomyosin interactions. The results of the present paper are consistent with acetylation providing a mechanism for modulating the formation and stability of Cdc8 polymers within the fission yeast cell. The data also provide evidence for a mechanism in which Tm dimers form end-to-end polymers on the actin filament, consistent with a co-operative model for Tm binding to actin.

Original languageEnglish (US)
Pages (from-to)265-273
Number of pages9
JournalBiochemical Journal
Volume438
Issue number2
DOIs
StatePublished - Sep 1 2011
Externally publishedYes

Fingerprint

Tropomyosin
Myosins
Actins
Polymers
Schizosaccharomyces
Dimers
Actin Cytoskeleton
Yeast
Proteins
Acetylation
Actomyosin
Protein Stability
Nucleic Acid Regulatory Sequences
Mutant Proteins
Methionine
Substitution reactions
Cells

Keywords

  • Acetylation
  • Cdc8
  • Coiled-coil
  • Fission yeast
  • Schizosaccharomyces pombe
  • Tropomyosin

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Cite this

Altering the stability of the Cdc8 overlap region modulates the ability of this tropomyosin to bind co-operatively to actin and regulate myosin. / East, Daniel A.; Sousa, Duncan; Martin, Stephen R.; Edwards, Thomas A.; Lehman, William; Mulvihill, Daniel P.

In: Biochemical Journal, Vol. 438, No. 2, 01.09.2011, p. 265-273.

Research output: Contribution to journalArticle

East, Daniel A. ; Sousa, Duncan ; Martin, Stephen R. ; Edwards, Thomas A. ; Lehman, William ; Mulvihill, Daniel P. / Altering the stability of the Cdc8 overlap region modulates the ability of this tropomyosin to bind co-operatively to actin and regulate myosin. In: Biochemical Journal. 2011 ; Vol. 438, No. 2. pp. 265-273.
@article{a8f44b14dd7a486bb4fa92f25ae2d9cf,
title = "Altering the stability of the Cdc8 overlap region modulates the ability of this tropomyosin to bind co-operatively to actin and regulate myosin",
abstract = "Tm(tropomyosin) is an evolutionarily conserved α-helical coiled-coil protein, dimers of which form end-to-end polymers capable of associating with and stabilizing actin filaments, and regulating myosin function. The fission yeast Schizosaccharomyces pombe possesses a single essential Tm, Cdc8, which can be acetylated on its N-terminal methionine residue to increase its affinity for actin and enhance its ability to regulate myosin function. We have designed and generated a number of novel Cdc8 mutant proteins with N-terminal substitutions to explore how stability of the Cdc8 overlap region affects the regulatory function of this Tm. By correlating the stability of each protein, its propensity to form stable polymers, its ability to associate with actin and to regulatemyosin,we have shownthat the stability of the N-terminal of the Cdc8 α-helix is crucial for Tm function. In addition we have identified a novel Cdc8 mutant with increased N-terminal stability, dimers of which are capable of forming Tm polymers significantly longer than the wild-type protein. This protein had a reduced affinity for actin with respect to wild-type, andwas unable to regulate actomyosin interactions. The results of the present paper are consistent with acetylation providing a mechanism for modulating the formation and stability of Cdc8 polymers within the fission yeast cell. The data also provide evidence for a mechanism in which Tm dimers form end-to-end polymers on the actin filament, consistent with a co-operative model for Tm binding to actin.",
keywords = "Acetylation, Cdc8, Coiled-coil, Fission yeast, Schizosaccharomyces pombe, Tropomyosin",
author = "East, {Daniel A.} and Duncan Sousa and Martin, {Stephen R.} and Edwards, {Thomas A.} and William Lehman and Mulvihill, {Daniel P.}",
year = "2011",
month = "9",
day = "1",
doi = "10.1042/BJ20101316",
language = "English (US)",
volume = "438",
pages = "265--273",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",
number = "2",

}

TY - JOUR

T1 - Altering the stability of the Cdc8 overlap region modulates the ability of this tropomyosin to bind co-operatively to actin and regulate myosin

AU - East, Daniel A.

AU - Sousa, Duncan

AU - Martin, Stephen R.

AU - Edwards, Thomas A.

AU - Lehman, William

AU - Mulvihill, Daniel P.

PY - 2011/9/1

Y1 - 2011/9/1

N2 - Tm(tropomyosin) is an evolutionarily conserved α-helical coiled-coil protein, dimers of which form end-to-end polymers capable of associating with and stabilizing actin filaments, and regulating myosin function. The fission yeast Schizosaccharomyces pombe possesses a single essential Tm, Cdc8, which can be acetylated on its N-terminal methionine residue to increase its affinity for actin and enhance its ability to regulate myosin function. We have designed and generated a number of novel Cdc8 mutant proteins with N-terminal substitutions to explore how stability of the Cdc8 overlap region affects the regulatory function of this Tm. By correlating the stability of each protein, its propensity to form stable polymers, its ability to associate with actin and to regulatemyosin,we have shownthat the stability of the N-terminal of the Cdc8 α-helix is crucial for Tm function. In addition we have identified a novel Cdc8 mutant with increased N-terminal stability, dimers of which are capable of forming Tm polymers significantly longer than the wild-type protein. This protein had a reduced affinity for actin with respect to wild-type, andwas unable to regulate actomyosin interactions. The results of the present paper are consistent with acetylation providing a mechanism for modulating the formation and stability of Cdc8 polymers within the fission yeast cell. The data also provide evidence for a mechanism in which Tm dimers form end-to-end polymers on the actin filament, consistent with a co-operative model for Tm binding to actin.

AB - Tm(tropomyosin) is an evolutionarily conserved α-helical coiled-coil protein, dimers of which form end-to-end polymers capable of associating with and stabilizing actin filaments, and regulating myosin function. The fission yeast Schizosaccharomyces pombe possesses a single essential Tm, Cdc8, which can be acetylated on its N-terminal methionine residue to increase its affinity for actin and enhance its ability to regulate myosin function. We have designed and generated a number of novel Cdc8 mutant proteins with N-terminal substitutions to explore how stability of the Cdc8 overlap region affects the regulatory function of this Tm. By correlating the stability of each protein, its propensity to form stable polymers, its ability to associate with actin and to regulatemyosin,we have shownthat the stability of the N-terminal of the Cdc8 α-helix is crucial for Tm function. In addition we have identified a novel Cdc8 mutant with increased N-terminal stability, dimers of which are capable of forming Tm polymers significantly longer than the wild-type protein. This protein had a reduced affinity for actin with respect to wild-type, andwas unable to regulate actomyosin interactions. The results of the present paper are consistent with acetylation providing a mechanism for modulating the formation and stability of Cdc8 polymers within the fission yeast cell. The data also provide evidence for a mechanism in which Tm dimers form end-to-end polymers on the actin filament, consistent with a co-operative model for Tm binding to actin.

KW - Acetylation

KW - Cdc8

KW - Coiled-coil

KW - Fission yeast

KW - Schizosaccharomyces pombe

KW - Tropomyosin

UR - http://www.scopus.com/inward/record.url?scp=80051677828&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80051677828&partnerID=8YFLogxK

U2 - 10.1042/BJ20101316

DO - 10.1042/BJ20101316

M3 - Article

C2 - 21658004

AN - SCOPUS:80051677828

VL - 438

SP - 265

EP - 273

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 2

ER -