Direct interaction between the COG complex and the SM protein, Sly1, is required for Golgi SNARE pairing.
The crucial roles of Sec1/Munc18 (SM)-like proteins in membrane fusion have been evidenced in genetic and biochemical studies. SM proteins interact directly with SNAREs and contribute to SNARE pairing by a yet unclear mechanism. Here, we show that the SM protein, Sly1, interacts directly with the conserved oligomeric Golgi (COG) tethering complex. The Sly1-COG interaction is mediated by the Cog4 subunit, which also interacts with Syntaxin 5 through a different binding site. We provide evidence that disruption of Cog4-Sly1 interaction impairs pairing of SNAREs involved in intra-Golgi transport thereby markedly attenuating Golgi-to-ER retrograde transport. These results highlight the mechanism by which SM proteins link tethering to SNAREpin assembly.
Laufman
Orly
O
Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
Kedan
Amir
A
Hong
Wanjin
W
Lev
Sima
S
D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D050765:Qa-SNARE Proteins / Q000378:metabolism*; D016415:Sequence Alignment; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000378:metabolism*
D033942:Adaptor Proteins, Vesicular Transport; C542474:COG4 protein, human; D002352:Carrier Proteins; D050765:Qa-SNARE Proteins; C527528:SCFD1 protein, human; D033921:Vesicular Transport Proteins