Abstract
The t-SNARE in a late Golgi compartment (Tlg2p) syntaxin is required for endocytosis and localization of cycling proteins to the late Golgi compartment in yeast. We show here that Tlg2p assembles with two light chains, Tlg1p and Vti1p, to form a functional t-SNARE that mediates fusion, specifically with the v-SNAREs Snc1p and Snc2p. In vitro, this t-SNARE is inert, locked in a nonfunctional state, unless it is activated for fusion. Activation can be mediated by a peptide derived from the v-SNARE, which likely bypasses additional regulatory proteins in the cell. Locking t-SNAREs creates the potential for spatial and temporal regulation of fusion by signaling processes that unleash their fusion capacity.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Amino Acid Sequence
-
Carrier Proteins / genetics
-
Carrier Proteins / metabolism
-
Endocytosis / physiology*
-
Fungal Proteins / genetics
-
Fungal Proteins / metabolism
-
Golgi Apparatus / metabolism*
-
Membrane Fusion / physiology*
-
Membrane Proteins / genetics
-
Membrane Proteins / metabolism*
-
Membrane Transport Proteins*
-
Molecular Sequence Data
-
Protein Transport / physiology
-
Qa-SNARE Proteins
-
Qb-SNARE Proteins
-
R-SNARE Proteins
-
SNARE Proteins
-
Saccharomyces cerevisiae
-
Saccharomyces cerevisiae Proteins*
-
Vesicular Transport Proteins*
Substances
-
Carrier Proteins
-
Fungal Proteins
-
Membrane Proteins
-
Membrane Transport Proteins
-
Qa-SNARE Proteins
-
Qb-SNARE Proteins
-
R-SNARE Proteins
-
SNARE Proteins
-
SNC2 protein, S cerevisiae
-
Saccharomyces cerevisiae Proteins
-
TLG2 protein, S cerevisiae
-
VTI1 protein, S cerevisiae
-
Vesicular Transport Proteins