TY - JOUR
T1 - Cutting edge
T2 - Tapasin is retained in the endoplasmic reticulum by dynamic clustering and exclusion from endoplasmic reticulum exit sites
AU - Pentcheva, Tsvetelina
AU - Spiliotis, Elias T.
AU - Edidin, Michael
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2002/2/15
Y1 - 2002/2/15
N2 - Tapasin retains empty or suboptimally loaded MHC class I molecules in the endoplasmic reticulum (ER). However, the molecular mechanism of this process and how tapasin itself is retained in the ER are unknown. These questions were addressed by tagging tapasin with the cyan fluorescent protein or yellow fluorescent protein (YFP) and probing the distribution and mobility of the tagged proteins. YFP-tapasin molecules were functional and could be isolated in association with TAP, as reported for native tapasin. YFP-tapasin was excluded from ER exit sites even after accumulation of secretory cargo due to disrupted anterograde traffic. Almost all tapasin molecules were clustered, and these clusters diffused freely in the ER. Tapasin oligomers appear to be retained by the failure of the export machinery to recognize them as cargo.
AB - Tapasin retains empty or suboptimally loaded MHC class I molecules in the endoplasmic reticulum (ER). However, the molecular mechanism of this process and how tapasin itself is retained in the ER are unknown. These questions were addressed by tagging tapasin with the cyan fluorescent protein or yellow fluorescent protein (YFP) and probing the distribution and mobility of the tagged proteins. YFP-tapasin molecules were functional and could be isolated in association with TAP, as reported for native tapasin. YFP-tapasin was excluded from ER exit sites even after accumulation of secretory cargo due to disrupted anterograde traffic. Almost all tapasin molecules were clustered, and these clusters diffused freely in the ER. Tapasin oligomers appear to be retained by the failure of the export machinery to recognize them as cargo.
UR - http://www.scopus.com/inward/record.url?scp=0037083359&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037083359&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.168.4.1538
DO - 10.4049/jimmunol.168.4.1538
M3 - Article
C2 - 11823478
AN - SCOPUS:0037083359
VL - 168
SP - 1538
EP - 1541
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 4
ER -