Association of tubulin carboxypeptidase with microtubules in living cells

María A. Contin, Juan J. Sironi, Héctor S. Barra, Carlos A. Arce

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Tubulin carboxypeptidase is the enzyme that releases the C-terminal tyrosine from α-tubulin, converting tyrosine-terminated (Tyr) to detyrosinated (Glu) tubulin. The present study demonstrates that this enzyme is associated with microtubules in living cells. We extracted cultured cells (COS-7) with Triton X-100 under microtubule-stabilizing conditions and found tubulin carboxypeptidase activity in the cytoskeleton fraction. We ruled out, by using several control experiments, the possibility that this result was due to contamination of the isolated cytoskeletons by non-associated proteins contained in the detergent fraction or to an artifact in vitro during the extraction procedure. The associated carboxypeptidase activity showed characteristics similar to those of brain tubulin carboxypeptidase and different from those of pancreatic carboxypeptidase A. In comparison with cultures at confluence, those at low cell density contained small (if any) amounts of carboxypeptidase activity associated with microtubules. In addition, the enzyme was shown to be associated only with cold-labile microtubules. The tubulin carboxypeptidase/microtubule association was also demonstrated in Chinese hamster ovary, NIH 3T3 and PC12 cells. Interestingly, this association was not observed in cultured embryonic brain cells. Our results demonstrate that tubulin carboxypeptidase is indeed associated with microtubules in living cells. Furthermore, the findings that this association occurs with a subset of microtubules and that its magnitude depends on the degree of confluence of the cell culture indicate that it could be part of the mechanism that regulates the tyrosination state of microtubules.

Original languageEnglish (US)
Pages (from-to)463-471
Number of pages9
JournalBiochemical Journal
Volume339
Issue number2
DOIs
StatePublished - Apr 15 1999
Externally publishedYes

Fingerprint

Microtubules
Cells
Carboxypeptidases
Brain
Enzymes
Carboxypeptidases A
Cytoskeleton
Octoxynol
Tubulin
Cell culture
Detergents
Tyrosine
Contamination
NIH 3T3 Cells
tyrosyltubulin carboxypeptidase
PC12 Cells
Cricetulus
Artifacts
Ovary
Cultured Cells

Keywords

  • Detyrosination
  • Post-translational modification
  • Tyrosination

ASJC Scopus subject areas

  • Biochemistry

Cite this

Association of tubulin carboxypeptidase with microtubules in living cells. / Contin, María A.; Sironi, Juan J.; Barra, Héctor S.; Arce, Carlos A.

In: Biochemical Journal, Vol. 339, No. 2, 15.04.1999, p. 463-471.

Research output: Contribution to journalArticle

Contin, María A. ; Sironi, Juan J. ; Barra, Héctor S. ; Arce, Carlos A. / Association of tubulin carboxypeptidase with microtubules in living cells. In: Biochemical Journal. 1999 ; Vol. 339, No. 2. pp. 463-471.
@article{e7819cc184c14464951472aeb3234b2f,
title = "Association of tubulin carboxypeptidase with microtubules in living cells",
abstract = "Tubulin carboxypeptidase is the enzyme that releases the C-terminal tyrosine from α-tubulin, converting tyrosine-terminated (Tyr) to detyrosinated (Glu) tubulin. The present study demonstrates that this enzyme is associated with microtubules in living cells. We extracted cultured cells (COS-7) with Triton X-100 under microtubule-stabilizing conditions and found tubulin carboxypeptidase activity in the cytoskeleton fraction. We ruled out, by using several control experiments, the possibility that this result was due to contamination of the isolated cytoskeletons by non-associated proteins contained in the detergent fraction or to an artifact in vitro during the extraction procedure. The associated carboxypeptidase activity showed characteristics similar to those of brain tubulin carboxypeptidase and different from those of pancreatic carboxypeptidase A. In comparison with cultures at confluence, those at low cell density contained small (if any) amounts of carboxypeptidase activity associated with microtubules. In addition, the enzyme was shown to be associated only with cold-labile microtubules. The tubulin carboxypeptidase/microtubule association was also demonstrated in Chinese hamster ovary, NIH 3T3 and PC12 cells. Interestingly, this association was not observed in cultured embryonic brain cells. Our results demonstrate that tubulin carboxypeptidase is indeed associated with microtubules in living cells. Furthermore, the findings that this association occurs with a subset of microtubules and that its magnitude depends on the degree of confluence of the cell culture indicate that it could be part of the mechanism that regulates the tyrosination state of microtubules.",
keywords = "Detyrosination, Post-translational modification, Tyrosination",
author = "Contin, {Mar{\'i}a A.} and Sironi, {Juan J.} and Barra, {H{\'e}ctor S.} and Arce, {Carlos A.}",
year = "1999",
month = "4",
day = "15",
doi = "10.1042/0264-6021:3390463",
language = "English (US)",
volume = "339",
pages = "463--471",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",
number = "2",

}

TY - JOUR

T1 - Association of tubulin carboxypeptidase with microtubules in living cells

AU - Contin, María A.

AU - Sironi, Juan J.

AU - Barra, Héctor S.

AU - Arce, Carlos A.

PY - 1999/4/15

Y1 - 1999/4/15

N2 - Tubulin carboxypeptidase is the enzyme that releases the C-terminal tyrosine from α-tubulin, converting tyrosine-terminated (Tyr) to detyrosinated (Glu) tubulin. The present study demonstrates that this enzyme is associated with microtubules in living cells. We extracted cultured cells (COS-7) with Triton X-100 under microtubule-stabilizing conditions and found tubulin carboxypeptidase activity in the cytoskeleton fraction. We ruled out, by using several control experiments, the possibility that this result was due to contamination of the isolated cytoskeletons by non-associated proteins contained in the detergent fraction or to an artifact in vitro during the extraction procedure. The associated carboxypeptidase activity showed characteristics similar to those of brain tubulin carboxypeptidase and different from those of pancreatic carboxypeptidase A. In comparison with cultures at confluence, those at low cell density contained small (if any) amounts of carboxypeptidase activity associated with microtubules. In addition, the enzyme was shown to be associated only with cold-labile microtubules. The tubulin carboxypeptidase/microtubule association was also demonstrated in Chinese hamster ovary, NIH 3T3 and PC12 cells. Interestingly, this association was not observed in cultured embryonic brain cells. Our results demonstrate that tubulin carboxypeptidase is indeed associated with microtubules in living cells. Furthermore, the findings that this association occurs with a subset of microtubules and that its magnitude depends on the degree of confluence of the cell culture indicate that it could be part of the mechanism that regulates the tyrosination state of microtubules.

AB - Tubulin carboxypeptidase is the enzyme that releases the C-terminal tyrosine from α-tubulin, converting tyrosine-terminated (Tyr) to detyrosinated (Glu) tubulin. The present study demonstrates that this enzyme is associated with microtubules in living cells. We extracted cultured cells (COS-7) with Triton X-100 under microtubule-stabilizing conditions and found tubulin carboxypeptidase activity in the cytoskeleton fraction. We ruled out, by using several control experiments, the possibility that this result was due to contamination of the isolated cytoskeletons by non-associated proteins contained in the detergent fraction or to an artifact in vitro during the extraction procedure. The associated carboxypeptidase activity showed characteristics similar to those of brain tubulin carboxypeptidase and different from those of pancreatic carboxypeptidase A. In comparison with cultures at confluence, those at low cell density contained small (if any) amounts of carboxypeptidase activity associated with microtubules. In addition, the enzyme was shown to be associated only with cold-labile microtubules. The tubulin carboxypeptidase/microtubule association was also demonstrated in Chinese hamster ovary, NIH 3T3 and PC12 cells. Interestingly, this association was not observed in cultured embryonic brain cells. Our results demonstrate that tubulin carboxypeptidase is indeed associated with microtubules in living cells. Furthermore, the findings that this association occurs with a subset of microtubules and that its magnitude depends on the degree of confluence of the cell culture indicate that it could be part of the mechanism that regulates the tyrosination state of microtubules.

KW - Detyrosination

KW - Post-translational modification

KW - Tyrosination

UR - http://www.scopus.com/inward/record.url?scp=0033560998&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033560998&partnerID=8YFLogxK

U2 - 10.1042/0264-6021:3390463

DO - 10.1042/0264-6021:3390463

M3 - Article

C2 - 10191280

AN - SCOPUS:0033560998

VL - 339

SP - 463

EP - 471

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 2

ER -