sentence: Because these structures reassemble first to regenerate cis-Golgi cisternae after BFA removal , we propose that they function as “ seeds ” of the Golgi stacks by receiving the materials for cis-cisternae.In mammalian cells , Golgi enzymes are absorbed to the ER by BFA treatment , but GM130 and GRASP65 ( Golgi matrix proteins ) and some Golgi membrane proteins ( including mammalian homologues of SYP31 , RER1 , and ERD2 ) remain at punctate structures that localize adjacent to ERES ( Tang et al ., 1993 ; Nakamura et al ., 1995 ; F ü llekrug et al ., 1997a , b ; Seemann et al ., 2000 ; Ward et al ., 2001 ) .