Brefeldin A redistributes resident and itinerant Golgi proteins to the endoplasmic reticulum.

Abstract

Abstract. Brefeldin A (BFA) has been reported to block protein transport from the ER and cause disassembly of the Golgi complex. We have examined the effects of BFA on the transport and processing of the vesicular stomatitis virus G protein, a model integral membrane protein. Delivery of G protein to the cell surface was reversibly blocked by 6 #g/ml BFA. Pulse-label experiments revealed that in the presence of BFA, G protein became completely resistant to endoglycosidase H digestion. Addition of sialic acid, a trans-Golgi event, was not observed. Despite processing by cis-and medial Golgi enzymes, G protein was localized by indirect immunofluorescence to a reticular distribution characteristic of the ER. By preventing transport of G protein from the ER with the metabolic inhibitor carbonyl cyanide m-chlorophenylhydrazone or by use of the temperature-sensitive mutant ts045, which is restricted to the ER at 40°C, we showed that processing of G protein occurred in the ER and was not due to retention of newly synthesized Golgi enzymes. Rather, redistribution of preexisting cis and medial Golgi enzymes to the ER occurred as soon as 2.5 min after addition of BFA, and was complete by 10-15 min. Delivery of Golgi enzymes to the ER was energy dependent and occurred only at temperatures >~20°C. BFA also induced retrograde transport of G protein from the medial Golgi to the ER. Golgi enzymes were completely recovered from the ER 10 min after removal of BFA. These findings demonstrate that BFA induces retrograde transport of both resident and itinerant Golgi proteins to the ER in a fully reversible manner.

Unique characteristics of Ca 2+ homeostasis of the trans -Golgi compartment

“…Addition of histamine (Fig. 2D) To demonstrate that our probe is able to sense reduction in [Ca 2+ ] induced by histamine or CPA when expressed in a subcompartment where the two drug targets (i.e., IP 3 Rs and SERCA) are present, we take advantage, as a tool, of brefeldin A (BFA), a drug known to block the forward, but not the backward, flow of vesicles in the GA (25). Upon BFA treatment many proteins of the GA move slowly back into the ER and thus it is predicted that also Go-D1cpv should move in that cell com- partment (SI Text S1).…”

Involvement of Secretory and Endosomal Compartments in Presentation of an Exogenous Self-Glycolipid to Type II NKT Cells

“…Brefeldin A disrupts anterograde protein transport from ER to Golgi (27) and induces retrograde transport of both resident and itinerant Golgi proteins to the ER in a fully reversible manner (28). The presentation of both lyso-sulfatide as well as ␣GalCer was not inhibited in the presence of brefeldin A (Fig.…”

Antigen Targeting to CD11b Allows Efficient Presentation of CD4+ and CD8+ T Cell Epitopes and In Vivo Th1-Polarized T Cell Priming

“…Thus, newly synthesized proteins are necessary for both MHC I and MHC II-restricted presentation of the CyaA AC domain. To determine whether MHC II molecules that present the MalE 100 -114 peptide reach early and late endosomes toward Golgi, we used BFA, an inhibitor of Golgi transport (44,45). The presentation of the MalE 100 -114 epitope after its delivery to BMDC by CyaA-MalE-OVA or MalE protein was totally abrogated by BFA (Fig.…”