PMID- 20976103
OWN - NLM
STAT- MEDLINE
DCOM- 20110307
LR  - 20211020
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 5
IP  - 10
DP  - 2010 Oct 18
TI  - Regulation of STIM1 and SOCE by the ubiquitin-proteasome system (UPS).
PG  - e13465
LID - 10.1371/journal.pone.0013465 [doi]
LID - e13465
AB  - The ubiquitin proteasome system (UPS) mediates the majority of protein 
      degradation in eukaryotic cells. The UPS has recently emerged as a key 
      degradation pathway involved in synapse development and function. In order to 
      better understand the function of the UPS at synapses we utilized a genetic and 
      proteomic approach to isolate and identify novel candidate UPS substrates from 
      biochemically purified synaptic membrane preparations. Using these methods, we 
      have identified Stromal interacting molecule 1 (STIM1). STIM1 is as an 
      endoplasmic reticulum (ER) calcium sensor that has been shown to regulate 
      store-operated Ca(2+) entry (SOCE). We have characterized STIM1 in neurons, 
      finding STIM1 is expressed throughout development with stable, high expression in 
      mature neurons. As in non-excitable cells, STIM1 is distributed in a membranous 
      and punctate fashion in hippocampal neurons. In addition, a population of STIM1 
      was found to exist at synapses. Furthermore, using surface biotinylation and 
      live-cell labeling methods, we detect a subpopulation of STIM1 on the surface of 
      hippocampal neurons. The role of STIM1 as a regulator of SOCE has typically been 
      examined in non-excitable cell types. Therefore, we examined the role of the UPS 
      in STIM1 and SOCE function in HEK293 cells. While we find that STIM1 is 
      ubiquitinated, its stability is not altered by proteasome inhibitors in cells 
      under basal conditions or conditions that activate SOCE. However, we find that 
      surface STIM1 levels and thapsigargin (TG)-induced SOCE are significantly 
      increased in cells treated with proteasome inhibitors. Additionally, we find that 
      the overexpression of POSH (Plenty of SH3's), an E3 ubiquitin ligase recently 
      shown to be involved in the regulation of Ca(2+) homeostasis, leads to decreased 
      STIM1 surface levels. Together, these results provide evidence for previously 
      undescribed roles of the UPS in the regulation of STIM1 and SOCE function.
FAU - Keil, Jeffrey M
AU  - Keil JM
AD  - Section of Neurobiology, Department of Biological Sciences, University of 
      California San Diego, La Jolla, California, United States of America.
FAU - Shen, Zhouxin
AU  - Shen Z
FAU - Briggs, Steven P
AU  - Briggs SP
FAU - Patrick, Gentry N
AU  - Patrick GN
LA  - eng
GR  - NS054732/NS/NINDS NIH HHS/United States
GR  - R01 NS060847-01A2/NS/NINDS NIH HHS/United States
GR  - R01 NS060847/NS/NINDS NIH HHS/United States
GR  - R21 NS054732-02/NS/NINDS NIH HHS/United States
GR  - R21 NS054732/NS/NINDS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20101018
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 0 (DNA Primers)
RN  - 0 (Membrane Proteins)
RN  - 0 (Neoplasm Proteins)
RN  - 0 (STIM1 protein, human)
RN  - 0 (Stromal Interaction Molecule 1)
RN  - 0 (Ubiquitin)
RN  - 147336-22-9 (Green Fluorescent Proteins)
RN  - EC 3.4.25.1 (Proteasome Endopeptidase Complex)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Calcium/metabolism
MH  - Cell Line
MH  - DNA Primers
MH  - Green Fluorescent Proteins/metabolism
MH  - Hippocampus/metabolism
MH  - Homeostasis
MH  - Humans
MH  - Hydrolysis
MH  - Ion Transport
MH  - Membrane Proteins/*metabolism
MH  - Mice
MH  - Mice, Transgenic
MH  - Neoplasm Proteins/*metabolism
MH  - Neurons/metabolism
MH  - Proteasome Endopeptidase Complex/*metabolism
MH  - Stromal Interaction Molecule 1
MH  - Tandem Mass Spectrometry
MH  - Ubiquitin/*metabolism
PMC - PMC2956693
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2010/10/27 06:00
MHDA- 2011/03/08 06:00
PMCR- 2010/10/18
CRDT- 2010/10/27 06:00
PHST- 2010/06/19 00:00 [received]
PHST- 2010/09/07 00:00 [accepted]
PHST- 2010/10/27 06:00 [entrez]
PHST- 2010/10/27 06:00 [pubmed]
PHST- 2011/03/08 06:00 [medline]
PHST- 2010/10/18 00:00 [pmc-release]
AID - 10-PONE-RA-20038R1 [pii]
AID - 10.1371/journal.pone.0013465 [doi]
PST - epublish
SO  - PLoS One. 2010 Oct 18;5(10):e13465. doi: 10.1371/journal.pone.0013465.