Regulation of LIM-domain-binding 1 protein expression by ubiquitination of Lys134

Paul W. Howard, Shall F. Jue, David G. Ransom, Richard Maurer

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

LDB1 (LIM-domain-binding 1) is a cofactor that participates in formation of transcriptional regulatory complexes involving transcription factors containing LIM domains as well as other factors. The amount of LDB1 protein in cells has previously been shown to be modulated by RNF12 (RING finger protein 12). RNF12 is an E3 ubiquitin ligase that can target LDB1 for poly-ubiquitination and degradation via the proteasome. We find that in HEK (human embryonic kidney)-293 cells expression of RNF12 leads to mono-ubiquitination of LDB1 and increased levels of LDB1 protein. Mutagenesis studies identified Lys134 of LDB1 as the residue that is mono-ubiquitinated by RNF12. Mutation of Lys 134 of LDB1 to arginine blocks the formation of mono-ubiquitinated LDB1 and surprisingly also increases LDB1 protein expression in HEK-293 cells. This leads to a model in which Lys134 of LDB1 can be either mono-ubiquitinated, leading to stabilization, or poly-ubiquitinated, leading to degradation by the proteasome pathway. We also find that ubiquitin-LDB1 fusion proteins are stabilized in HEK-293 cells, offering further evidence that mono-ubiquitination stabilizes LDB1 in these cells. Expression in Xenopus laevis embryos of an LDB1 protein in which Lys134 is replaced with arginine leads to enhanced expression of the mutant protein as compared with the wildtype protein. These findings provide evidence that modification of Lys 134 can play a major role in regulating LDB1 expression.

Original languageEnglish (US)
Pages (from-to)127-136
Number of pages10
JournalBiochemical Journal
Volume429
Issue number1
DOIs
StatePublished - Jul 1 2010

Fingerprint

Ubiquitination
Carrier Proteins
Proteins
Proteasome Endopeptidase Complex
Kidney
Arginine
Ubiquitin-Protein Ligases
Xenopus laevis
Mutant Proteins
Ubiquitin
Mutagenesis
Transcription Factors
Embryonic Structures
Degradation
Mutation
Fusion reactions
Stabilization

Keywords

  • LIM-domain-binding 1 (LDB1)
  • Post-translational modification
  • Proteasome
  • Protein degradation
  • RING finger protein 12 (RNF12)
  • Ubiquitin ligase

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology
  • Medicine(all)

Cite this

Regulation of LIM-domain-binding 1 protein expression by ubiquitination of Lys134 . / Howard, Paul W.; Jue, Shall F.; Ransom, David G.; Maurer, Richard.

In: Biochemical Journal, Vol. 429, No. 1, 01.07.2010, p. 127-136.

Research output: Contribution to journalArticle

Howard, Paul W. ; Jue, Shall F. ; Ransom, David G. ; Maurer, Richard. / Regulation of LIM-domain-binding 1 protein expression by ubiquitination of Lys134 . In: Biochemical Journal. 2010 ; Vol. 429, No. 1. pp. 127-136.
@article{c8cfd5cae95348c8add9a81c8b681f27,
title = "Regulation of LIM-domain-binding 1 protein expression by ubiquitination of Lys134",
abstract = "LDB1 (LIM-domain-binding 1) is a cofactor that participates in formation of transcriptional regulatory complexes involving transcription factors containing LIM domains as well as other factors. The amount of LDB1 protein in cells has previously been shown to be modulated by RNF12 (RING finger protein 12). RNF12 is an E3 ubiquitin ligase that can target LDB1 for poly-ubiquitination and degradation via the proteasome. We find that in HEK (human embryonic kidney)-293 cells expression of RNF12 leads to mono-ubiquitination of LDB1 and increased levels of LDB1 protein. Mutagenesis studies identified Lys134 of LDB1 as the residue that is mono-ubiquitinated by RNF12. Mutation of Lys 134 of LDB1 to arginine blocks the formation of mono-ubiquitinated LDB1 and surprisingly also increases LDB1 protein expression in HEK-293 cells. This leads to a model in which Lys134 of LDB1 can be either mono-ubiquitinated, leading to stabilization, or poly-ubiquitinated, leading to degradation by the proteasome pathway. We also find that ubiquitin-LDB1 fusion proteins are stabilized in HEK-293 cells, offering further evidence that mono-ubiquitination stabilizes LDB1 in these cells. Expression in Xenopus laevis embryos of an LDB1 protein in which Lys134 is replaced with arginine leads to enhanced expression of the mutant protein as compared with the wildtype protein. These findings provide evidence that modification of Lys 134 can play a major role in regulating LDB1 expression.",
keywords = "LIM-domain-binding 1 (LDB1), Post-translational modification, Proteasome, Protein degradation, RING finger protein 12 (RNF12), Ubiquitin ligase",
author = "Howard, {Paul W.} and Jue, {Shall F.} and Ransom, {David G.} and Richard Maurer",
year = "2010",
month = "7",
day = "1",
doi = "10.1042/BJ20091461",
language = "English (US)",
volume = "429",
pages = "127--136",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",
number = "1",

}

TY - JOUR

T1 - Regulation of LIM-domain-binding 1 protein expression by ubiquitination of Lys134

AU - Howard, Paul W.

AU - Jue, Shall F.

AU - Ransom, David G.

AU - Maurer, Richard

PY - 2010/7/1

Y1 - 2010/7/1

N2 - LDB1 (LIM-domain-binding 1) is a cofactor that participates in formation of transcriptional regulatory complexes involving transcription factors containing LIM domains as well as other factors. The amount of LDB1 protein in cells has previously been shown to be modulated by RNF12 (RING finger protein 12). RNF12 is an E3 ubiquitin ligase that can target LDB1 for poly-ubiquitination and degradation via the proteasome. We find that in HEK (human embryonic kidney)-293 cells expression of RNF12 leads to mono-ubiquitination of LDB1 and increased levels of LDB1 protein. Mutagenesis studies identified Lys134 of LDB1 as the residue that is mono-ubiquitinated by RNF12. Mutation of Lys 134 of LDB1 to arginine blocks the formation of mono-ubiquitinated LDB1 and surprisingly also increases LDB1 protein expression in HEK-293 cells. This leads to a model in which Lys134 of LDB1 can be either mono-ubiquitinated, leading to stabilization, or poly-ubiquitinated, leading to degradation by the proteasome pathway. We also find that ubiquitin-LDB1 fusion proteins are stabilized in HEK-293 cells, offering further evidence that mono-ubiquitination stabilizes LDB1 in these cells. Expression in Xenopus laevis embryos of an LDB1 protein in which Lys134 is replaced with arginine leads to enhanced expression of the mutant protein as compared with the wildtype protein. These findings provide evidence that modification of Lys 134 can play a major role in regulating LDB1 expression.

AB - LDB1 (LIM-domain-binding 1) is a cofactor that participates in formation of transcriptional regulatory complexes involving transcription factors containing LIM domains as well as other factors. The amount of LDB1 protein in cells has previously been shown to be modulated by RNF12 (RING finger protein 12). RNF12 is an E3 ubiquitin ligase that can target LDB1 for poly-ubiquitination and degradation via the proteasome. We find that in HEK (human embryonic kidney)-293 cells expression of RNF12 leads to mono-ubiquitination of LDB1 and increased levels of LDB1 protein. Mutagenesis studies identified Lys134 of LDB1 as the residue that is mono-ubiquitinated by RNF12. Mutation of Lys 134 of LDB1 to arginine blocks the formation of mono-ubiquitinated LDB1 and surprisingly also increases LDB1 protein expression in HEK-293 cells. This leads to a model in which Lys134 of LDB1 can be either mono-ubiquitinated, leading to stabilization, or poly-ubiquitinated, leading to degradation by the proteasome pathway. We also find that ubiquitin-LDB1 fusion proteins are stabilized in HEK-293 cells, offering further evidence that mono-ubiquitination stabilizes LDB1 in these cells. Expression in Xenopus laevis embryos of an LDB1 protein in which Lys134 is replaced with arginine leads to enhanced expression of the mutant protein as compared with the wildtype protein. These findings provide evidence that modification of Lys 134 can play a major role in regulating LDB1 expression.

KW - LIM-domain-binding 1 (LDB1)

KW - Post-translational modification

KW - Proteasome

KW - Protein degradation

KW - RING finger protein 12 (RNF12)

KW - Ubiquitin ligase

UR - http://www.scopus.com/inward/record.url?scp=77954489796&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77954489796&partnerID=8YFLogxK

U2 - 10.1042/BJ20091461

DO - 10.1042/BJ20091461

M3 - Article

VL - 429

SP - 127

EP - 136

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 1

ER -