There’s a prevailing dogma in the field of cell biology. When it comes to transmembrane protein trafficking—the act of molecules crossing cellular membranes—proteins need to be unfolded to cross, otherwise they’re too bulky to fit through membrane pores.
A new study, published by Biophysics Graduate Group member Professor Steven Theg, Department of Plant Biology, and his colleagues in The Plant Cell, reexamines how protein trafficking occurs in the chloroplasts of green plants. The researchers found that surprisingly large proteins don’t require unfolding to cross the chloroplast membrane. They can do so while folded.