Differential roles for STIM1 and STIM2 in store-operated calcium entry in rat neurons

The interaction between Ca(2+) sensors STIM1 and STIM2 and Ca(2+) channel-forming protein ORAI1 is a crucial element of store-operated calcium entry (SOCE) in non-excitable cells. However, the molecular mechanism of SOCE in neurons remains unclear. We addressed this issue by establishing the presenc...

Full description

Saved in:
Bibliographic Details
Published in:PloS one 2011-04, Vol.6 (4), p.e19285
Main Authors: Gruszczynska-Biegala, Joanna, Pomorski, Pawel, Wisniewska, Marta B, Kuznicki, Jacek
Format: Article
Language:English
Subjects:
Adenosine triphosphatase
Alzheimer's disease
Alzheimers disease
Animals
Azepines - pharmacology
Bacterial Proteins - metabolism
Biochemistry
Biology
Boron Compounds - pharmacology
Brain
Calcium
Calcium (intracellular)
Calcium - metabolism
Calcium channels
Calcium Channels - metabolism
Calcium homeostasis
Calcium influx
Calcium-Binding Proteins - genetics
Calcium-Binding Proteins - metabolism
Cell Membrane - drug effects
Cell Membrane - metabolism
Cerebral Cortex - cytology
Chelating Agents - pharmacology
Endoplasmic reticulum
Endoplasmic Reticulum - drug effects
Endoplasmic Reticulum - metabolism
Fura-2
Gene expression
Gene Expression Regulation - drug effects
Homeostasis
Inhibitors
Laboratories
Luminescent Proteins - metabolism
Membrane Glycoproteins - genetics
Membrane Glycoproteins - metabolism
Membrane Proteins - genetics
Membrane Proteins - metabolism
mRNA
Neurodegeneration
Neurons
Neurons - cytology
Neurons - drug effects
Neurons - metabolism
ORAI1 Protein
Polymerase chain reaction
Proteins
Rats
Rats, Wistar
Reverse Transcriptase Polymerase Chain Reaction
RNA
RNA, Messenger - genetics
RNA, Messenger - metabolism
Sensors
STIM1 protein
Stromal Interaction Molecule 1
Stromal Interaction Molecule 2
Subcellular Fractions - drug effects
Subcellular Fractions - metabolism
Thapsigargin
Thapsigargin - pharmacology
Transfection
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The interaction between Ca(2+) sensors STIM1 and STIM2 and Ca(2+) channel-forming protein ORAI1 is a crucial element of store-operated calcium entry (SOCE) in non-excitable cells. However, the molecular mechanism of SOCE in neurons remains unclear. We addressed this issue by establishing the presence and function of STIM proteins. Real-time polymerase chain reaction from cortical neurons showed that these cells contain significant amounts of Stim1 and Stim2 mRNA. Thapsigargin (TG) treatment increased the amount of both endogenous STIM proteins in neuronal membrane fractions. The number of YFP-STIM1/ORAI1 and YFP-STIM2/ORAI1 complexes was also enhanced by such treatment. The differences observed in the number of STIM1 and STIM2 complexes under SOCE conditions and the differential sensitivity to SOCE inhibitors suggest their distinct roles. Endoplasmic reticulum (ER) store depletion by TG enhanced intracellular Ca(2+) levels in loaded with Fura-2 neurons transfected with YFP-STIM1 and ORAI1, but not with YFP-STIM2 and ORAI1, which correlated well with the number of complexes formed. Moreover, the SOCE inhibitors ML-9 and 2-APB reduced Ca(2+) influx in neurons expressing YFP-STIM1/ORAI1 but produced no effect in cells transfected with YFP-STIM2/ORAI1. Moreover, in neurons transfected with YFP-STIM2/ORAI1, the increase in constitutive calcium entry was greater than with YFP-STIM1/ORAI1. Our data indicate that both STIM proteins are involved in calcium homeostasis in neurons. STIM1 mainly activates SOCE, whereas STIM2 regulates resting Ca(2+) levels in the ER and Ca(2+) leakage with the additional involvement of STIM1.
ISSN:1932-6203
1932-6203
DOI:10.1371/journal.pone.0019285