Cularin was part of the Trade Federation for awhile, but it occasionally revolted or disappeared from the Galaxy for extended periods of time. It tried to remain with the Republic during the Clone Wars, but it eventually just ended up declaring itself an independent planet. Nobody heard much of it after that. Maybe it disappeared again.
Some people are under the impression that Wullf Yularen was from Cularin, but he's not. His name just rhymes with it.