TY - JOUR
T1 - Multiple cargo binding sites on the COPII subunit Sec24p ensure capture of diverse membrane proteins into transport vesicles
AU - Miller, Elizabeth A.
AU - Beilharz, Traude H.
AU - Malkus, Per N.
AU - Lee, Marcus C.S.
AU - Hamamoto, Susan
AU - Orci, Lelio
AU - Schekman, Randy
N1 - Funding Information:
We are most grateful to Elena Mossessova and Jonathan Goldberg for sharing their structural data prior to publication and suggesting additional mutations in the Bet1p/Sys1p binding site. We thank Crystal Chan for preparing COPII proteins, Charlie Barlowe for providing antibodies against Erv41p and Erv46p, and Seth Harris for help with PyMOL. We thank members of the Schekman lab for support and critical comments, especially David Madden. This work was supported by HHMI (R.S.) and the Swiss National Science Foundation (L.O.). E.A.M. is a Fellow of the Jane Coffin Childs Memorial Fund for Medical Research. M.C.S.L. is supported by a long-term fellowship from the Human Frontiers Scientific Program.
PY - 2003/8/22
Y1 - 2003/8/22
N2 - We have characterized the mechanisms of cargo selection into ER-derived vesicles by the COPII subunit Sec24p. We identified a site on Sec24p that recognizes the v-SNARE Bet1p and show that packaging of a number of cargo molecules is disrupted when mutations are introduced at this site. Surprisingly, cargo proteins affected by these mutations did not share a single common sorting signal, nor were proteins sharing a putative class of signal affected to the same degree. We show that the same site is conserved as a cargo-interaction domain on the Sec24p homolog Lst1p, which only packages a subset of the cargoes recognized by Sec24p. Finally, we identified an additional mutation that defines another cargo binding domain on Sec24p, which specifically interacts with the SNARE Sec22p. Together, our data support a model whereby Sec24p proteins contain multiple independent cargo binding domains that allow for recognition of a diverse set of sorting signals.
AB - We have characterized the mechanisms of cargo selection into ER-derived vesicles by the COPII subunit Sec24p. We identified a site on Sec24p that recognizes the v-SNARE Bet1p and show that packaging of a number of cargo molecules is disrupted when mutations are introduced at this site. Surprisingly, cargo proteins affected by these mutations did not share a single common sorting signal, nor were proteins sharing a putative class of signal affected to the same degree. We show that the same site is conserved as a cargo-interaction domain on the Sec24p homolog Lst1p, which only packages a subset of the cargoes recognized by Sec24p. Finally, we identified an additional mutation that defines another cargo binding domain on Sec24p, which specifically interacts with the SNARE Sec22p. Together, our data support a model whereby Sec24p proteins contain multiple independent cargo binding domains that allow for recognition of a diverse set of sorting signals.
UR - http://www.scopus.com/inward/record.url?scp=0041526467&partnerID=8YFLogxK
U2 - 10.1016/S0092-8674(03)00609-3
DO - 10.1016/S0092-8674(03)00609-3
M3 - Article
C2 - 12941277
AN - SCOPUS:0041526467
SN - 0092-8674
VL - 114
SP - 497
EP - 509
JO - Cell
JF - Cell
IS - 4
ER -