Vesicle SNARE required for targeting and fusion of retrograde transport vesicles with the Golgi complex. Required for the integrity of the Golgi complex. Component of a SNARE complex consisting of STX5, YKT6, GOSR2 and BET1L. Present throughout the Golgi apparatus, with strongly increasing concentration from cis-Golgi to the trans-Golgi face of the stacks. Widely expressed. Highest levels in heart, liver, skeletal muscle and kidney.