What is "brefeldin a"

n. (context biochemistry English) A lactone antibiotic produced by fungal organisms such as ''Eupenicillium brefeldianum'', inhibiting transport of proteins from ER to Golgi and inducing retrograde protein transport from the Golgi apparatus to the endoplasmic reticulum.

Brefeldin A is a lactone antibiotic produced by fungal organisms such as Eupenicillium brefeldianum. Brefeldin A inhibits protein transport from the endoplasmic reticulum to the Golgi apparatus indirectly by preventing formation of COPI-mediated transport vesicles. Brefeldin A was initially isolated as an anti- viral antibiotic but is now primarily used in biological research to study protein transport.