PMID- 23479622
OWN - NLM
STAT- MEDLINE
DCOM- 20130523
LR  - 20220309
IS  - 1091-6490 (Electronic)
IS  - 0027-8424 (Print)
IS  - 0027-8424 (Linking)
VI  - 110
IP  - 13
DP  - 2013 Mar 26
TI  - AMPA receptor/TARP stoichiometry visualized by single-molecule subunit counting.
PG  - 5163-8
LID - 10.1073/pnas.1218765110 [doi]
AB  - Members of the transmembrane AMPA receptor-regulatory protein (TARP) family 
      modulate AMPA receptor (AMPA-R) trafficking and function. AMPA-Rs consist of four 
      pore-forming subunits. Previous studies show that TARPs are an integral part of 
      the AMPA-R complex, acting as accessory subunits for mature receptors in vivo. 
      The TARP/AMPA-R stoichiometry was previously measured indirectly and found to be 
      variable and dependent on TARP expression level, with at most four TARPs 
      associated with each AMPA-R complex. Here, we use a single-molecule technique in 
      live cells that selectively images proteins located in the plasma membrane to 
      directly count the number of TARPs associated with each AMPA-R complex. Although 
      individual GFP-tagged TARP subunits are observed as freely diffusing fluorescent 
      spots on the surface of Xenopus laevis oocytes when expressed alone, coexpression 
      with AMPA-R-mCherry immobilizes the stargazin-GFP spots at sites of 
      AMPA-R-mCherry, consistent with complex formation. We determined the number of 
      TARP molecules associated with each AMPA-R by counting bleaching steps for three 
      different TARP family members: gamma-2, gamma-3, and gamma-4. We confirm that the TARP/AMPA-R 
      stoichiometry depends on TARP expression level and discover that the maximum 
      number of TARPs per AMPA-R complex falls into two categories: up to four gamma-2 or 
      gamma-3 subunits, but rarely above two for gamma-4 subunit. This unexpected AMPA-R/TARP 
      stoichiometry difference has important implications for the assembly and function 
      of TARP/AMPA-R complexes.
FAU - Hastie, Peter
AU  - Hastie P
AD  - Department of Molecular and Cell Biology, University of California, Berkeley, CA 
      94720, USA.
FAU - Ulbrich, Maximilian H
AU  - Ulbrich MH
FAU - Wang, Hui-Li
AU  - Wang HL
FAU - Arant, Ryan J
AU  - Arant RJ
FAU - Lau, Anthony G
AU  - Lau AG
FAU - Zhang, Zhenjie
AU  - Zhang Z
FAU - Isacoff, Ehud Y
AU  - Isacoff EY
FAU - Chen, Lu
AU  - Chen L
LA  - eng
GR  - 1R01MH091193/MH/NIMH NIH HHS/United States
GR  - PN2 EY018241/EY/NEI NIH HHS/United States
GR  - R01 MH091193/MH/NIMH NIH HHS/United States
GR  - P50 MH086403/MH/NIMH NIH HHS/United States
GR  - 1P50MH086403/MH/NIMH NIH HHS/United States
GR  - R01NS35549/NS/NINDS NIH HHS/United States
GR  - 2PN2EY018241/EY/NEI NIH HHS/United States
GR  - R01 NS035549/NS/NINDS NIH HHS/United States
GR  - R01 MH069792/MH/NIMH NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20130311
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Cacng2 protein, rat)
RN  - 0 (Cacng4 protein, rat)
RN  - 0 (Calcium Channels)
RN  - 0 (Multiprotein Complexes)
RN  - 0 (Protein Subunits)
RN  - 0 (Receptors, AMPA)
RN  - 0 (Recombinant Proteins)
RN  - 147336-22-9 (Green Fluorescent Proteins)
SB  - IM
MH  - Animals
MH  - Calcium Channels/genetics/*metabolism
MH  - Green Fluorescent Proteins/genetics/metabolism
MH  - HEK293 Cells
MH  - Humans
MH  - Mice
MH  - Multiprotein Complexes/genetics/*metabolism
MH  - Protein Subunits/genetics/*metabolism
MH  - Rats
MH  - Receptors, AMPA/genetics/*metabolism
MH  - Recombinant Proteins/genetics/metabolism
MH  - Xenopus laevis
PMC - PMC3612642
COIS- The authors declare no conflict of interest.
EDAT- 2013/03/13 06:00
MHDA- 2013/05/25 06:00
PMCR- 2013/09/26
CRDT- 2013/03/13 06:00
PHST- 2013/03/13 06:00 [entrez]
PHST- 2013/03/13 06:00 [pubmed]
PHST- 2013/05/25 06:00 [medline]
PHST- 2013/09/26 00:00 [pmc-release]
AID - 1218765110 [pii]
AID - 201218765 [pii]
AID - 10.1073/pnas.1218765110 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 2013 Mar 26;110(13):5163-8. doi: 
      10.1073/pnas.1218765110. Epub 2013 Mar 11.