Role of the protonmotive force and of the state of the lipids in the in vivo protein secretion in Corynebacterium glutamicum, a gram-positive bacterium.
PS1 is a protein translocated across the cytoplasmic membrane of Corynebacterium glutamicum, a Gram-positive bacterium. Western blots of whole cell extracts showed the presence of two bands associated with the mature and the precursor forms. Addition of chloramphenicol led to the disappearance of the precursor form while dissipation of the protonmotive force (delta microH) prior to the addition of chloramphenicol prevented the maturation of the precursor. Dissipation of delta microH prior to a pulse chase experiment resulted in a complete block on translocation; regeneration of delta microH allowed the translocation of PS1 synthesized in its absence. On the other hand, dissipation of delta microH immediately after a pulse period had little effect on PS1 secretion. Lowering the temperature to 10 degrees C at the end of the pulse period completely inhibited secretion. The efficiency of secretion as a function of increasing temperature followed closely the order-to-disorder transition of the membrane lipids as detected by fluorescence anisotropy of diphenylhexatriene. Taken together, the results show that delta microH and the state of the lipids affect different steps of PS1 secretion.
Bayan
N
N
Laboratoire des Biomembranes, CNRS (UA 1116 and GDR 961), Université de Paris-Sud, Orsay, France.
Schrempp
S
S
Joliff
G
G
Leblon
G
G
Shechter
E
E
D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002462:Cell Membrane / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002701:Chloramphenicol; D003352:Corynebacterium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D003470:Culture Media; D004161:Diphenylhexatriene; D007425:Intracellular Membranes / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011522:Protons; D013696:Temperature
D003470:Culture Media; D008563:Membrane Lipids; D011506:Proteins; D011522:Protons; D004161:Diphenylhexatriene; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D002701:Chloramphenicol