Temperature-sensitive mutant of the Caenorhabditis elegans neurotoxic MEC-4(d) DEG/ENaC channel identifies a site required for trafficking or surface maintenance

Dewey C. Royal, Laura Blanchi, Mary Anne Royal, Michael Lizzio, Gargi Mukherjee, Yury O. Nunez, Monica Driscoll

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

DEG/ENaC channel subunits are two transmembrane domain proteins that assemble into heteromeric complexes to perform diverse biological functions that include sensory perception, electrolyte balance, and synaptic plasticity. Hyperactivation of neuronally expressed DEG/ENaCs that conduct both Na + and Ca2+, however, can potently induce necrotic neuronal death in vivo. For example, Caenorhabditis elegans DEG/ENaC MEC-4 comprises the core subunit of a touch-transducing ion channel critical for mechanosensation that when hyperactivated by a mec-4(d) mutation induces necrosis of the sensory neurons in which it is expressed. Thus, studies of the MEC-4 channel have provided insight into both normal channel biology and neurotoxicity mechanisms. Here we report on intragenic mec-4 mutations identified in a screen for suppressors of mec-4(d)-induced necrosis, with a focus on detailed characterization of allele bz2 that has the distinctive phenotype of inducing dramatic neuronal swelling without being fully penetrant for toxicity. The bz2 mutation encodes substitution A745T, which is situated in the intracellular C-terminal domain of MEC-4. We show that this substitution renders both MEC-4 and MEC-4(d) activity strongly temperature sensitive. In addition, we show that both in Xenopus oocytes and in vivo, substitution A745T disrupts channel trafficking or maintenance of the MEC-4 subunit at the cell surface. This is the first demonstration of a C-terminal domain that affects trafficking of a neuronally expressed DEG/ENaC. Moreover, this study reveals that neuronal swelling occurs prior to commitment to necrotic death and defines a powerful new tool for inducible necrosis initiation.

Original languageEnglish (US)
Pages (from-to)41976-41986
Number of pages11
JournalJournal of Biological Chemistry
Volume280
Issue number51
DOIs
StatePublished - Dec 23 2005

Fingerprint

Caenorhabditis elegans
Substitution reactions
Necrosis
Maintenance
Mutation
Temperature
Swelling
Neuronal Plasticity
Water-Electrolyte Balance
Touch
Sensory Receptor Cells
Xenopus
Ion Channels
Electrolytes
Neurons
Oocytes
Plasticity
Toxicity
Demonstrations
Alleles

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Royal, Dewey C. ; Blanchi, Laura ; Royal, Mary Anne ; Lizzio, Michael ; Mukherjee, Gargi ; Nunez, Yury O. ; Driscoll, Monica. / Temperature-sensitive mutant of the Caenorhabditis elegans neurotoxic MEC-4(d) DEG/ENaC channel identifies a site required for trafficking or surface maintenance. In: Journal of Biological Chemistry. 2005 ; Vol. 280, No. 51. pp. 41976-41986.
@article{1d006e0ac17248d0a9f9d60aab18a2ab,
title = "Temperature-sensitive mutant of the Caenorhabditis elegans neurotoxic MEC-4(d) DEG/ENaC channel identifies a site required for trafficking or surface maintenance",
abstract = "DEG/ENaC channel subunits are two transmembrane domain proteins that assemble into heteromeric complexes to perform diverse biological functions that include sensory perception, electrolyte balance, and synaptic plasticity. Hyperactivation of neuronally expressed DEG/ENaCs that conduct both Na + and Ca2+, however, can potently induce necrotic neuronal death in vivo. For example, Caenorhabditis elegans DEG/ENaC MEC-4 comprises the core subunit of a touch-transducing ion channel critical for mechanosensation that when hyperactivated by a mec-4(d) mutation induces necrosis of the sensory neurons in which it is expressed. Thus, studies of the MEC-4 channel have provided insight into both normal channel biology and neurotoxicity mechanisms. Here we report on intragenic mec-4 mutations identified in a screen for suppressors of mec-4(d)-induced necrosis, with a focus on detailed characterization of allele bz2 that has the distinctive phenotype of inducing dramatic neuronal swelling without being fully penetrant for toxicity. The bz2 mutation encodes substitution A745T, which is situated in the intracellular C-terminal domain of MEC-4. We show that this substitution renders both MEC-4 and MEC-4(d) activity strongly temperature sensitive. In addition, we show that both in Xenopus oocytes and in vivo, substitution A745T disrupts channel trafficking or maintenance of the MEC-4 subunit at the cell surface. This is the first demonstration of a C-terminal domain that affects trafficking of a neuronally expressed DEG/ENaC. Moreover, this study reveals that neuronal swelling occurs prior to commitment to necrotic death and defines a powerful new tool for inducible necrosis initiation.",
author = "Royal, {Dewey C.} and Laura Blanchi and Royal, {Mary Anne} and Michael Lizzio and Gargi Mukherjee and Nunez, {Yury O.} and Monica Driscoll",
year = "2005",
month = "12",
day = "23",
doi = "10.1074/jbc.M510732200",
language = "English (US)",
volume = "280",
pages = "41976--41986",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "51",

}

Temperature-sensitive mutant of the Caenorhabditis elegans neurotoxic MEC-4(d) DEG/ENaC channel identifies a site required for trafficking or surface maintenance. / Royal, Dewey C.; Blanchi, Laura; Royal, Mary Anne; Lizzio, Michael; Mukherjee, Gargi; Nunez, Yury O.; Driscoll, Monica.

In: Journal of Biological Chemistry, Vol. 280, No. 51, 23.12.2005, p. 41976-41986.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Temperature-sensitive mutant of the Caenorhabditis elegans neurotoxic MEC-4(d) DEG/ENaC channel identifies a site required for trafficking or surface maintenance

AU - Royal, Dewey C.

AU - Blanchi, Laura

AU - Royal, Mary Anne

AU - Lizzio, Michael

AU - Mukherjee, Gargi

AU - Nunez, Yury O.

AU - Driscoll, Monica

PY - 2005/12/23

Y1 - 2005/12/23

N2 - DEG/ENaC channel subunits are two transmembrane domain proteins that assemble into heteromeric complexes to perform diverse biological functions that include sensory perception, electrolyte balance, and synaptic plasticity. Hyperactivation of neuronally expressed DEG/ENaCs that conduct both Na + and Ca2+, however, can potently induce necrotic neuronal death in vivo. For example, Caenorhabditis elegans DEG/ENaC MEC-4 comprises the core subunit of a touch-transducing ion channel critical for mechanosensation that when hyperactivated by a mec-4(d) mutation induces necrosis of the sensory neurons in which it is expressed. Thus, studies of the MEC-4 channel have provided insight into both normal channel biology and neurotoxicity mechanisms. Here we report on intragenic mec-4 mutations identified in a screen for suppressors of mec-4(d)-induced necrosis, with a focus on detailed characterization of allele bz2 that has the distinctive phenotype of inducing dramatic neuronal swelling without being fully penetrant for toxicity. The bz2 mutation encodes substitution A745T, which is situated in the intracellular C-terminal domain of MEC-4. We show that this substitution renders both MEC-4 and MEC-4(d) activity strongly temperature sensitive. In addition, we show that both in Xenopus oocytes and in vivo, substitution A745T disrupts channel trafficking or maintenance of the MEC-4 subunit at the cell surface. This is the first demonstration of a C-terminal domain that affects trafficking of a neuronally expressed DEG/ENaC. Moreover, this study reveals that neuronal swelling occurs prior to commitment to necrotic death and defines a powerful new tool for inducible necrosis initiation.

AB - DEG/ENaC channel subunits are two transmembrane domain proteins that assemble into heteromeric complexes to perform diverse biological functions that include sensory perception, electrolyte balance, and synaptic plasticity. Hyperactivation of neuronally expressed DEG/ENaCs that conduct both Na + and Ca2+, however, can potently induce necrotic neuronal death in vivo. For example, Caenorhabditis elegans DEG/ENaC MEC-4 comprises the core subunit of a touch-transducing ion channel critical for mechanosensation that when hyperactivated by a mec-4(d) mutation induces necrosis of the sensory neurons in which it is expressed. Thus, studies of the MEC-4 channel have provided insight into both normal channel biology and neurotoxicity mechanisms. Here we report on intragenic mec-4 mutations identified in a screen for suppressors of mec-4(d)-induced necrosis, with a focus on detailed characterization of allele bz2 that has the distinctive phenotype of inducing dramatic neuronal swelling without being fully penetrant for toxicity. The bz2 mutation encodes substitution A745T, which is situated in the intracellular C-terminal domain of MEC-4. We show that this substitution renders both MEC-4 and MEC-4(d) activity strongly temperature sensitive. In addition, we show that both in Xenopus oocytes and in vivo, substitution A745T disrupts channel trafficking or maintenance of the MEC-4 subunit at the cell surface. This is the first demonstration of a C-terminal domain that affects trafficking of a neuronally expressed DEG/ENaC. Moreover, this study reveals that neuronal swelling occurs prior to commitment to necrotic death and defines a powerful new tool for inducible necrosis initiation.

UR - http://www.scopus.com/inward/record.url?scp=29644435614&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=29644435614&partnerID=8YFLogxK

U2 - 10.1074/jbc.M510732200

DO - 10.1074/jbc.M510732200

M3 - Article

C2 - 16239217

AN - SCOPUS:29644435614

VL - 280

SP - 41976

EP - 41986

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 51

ER -