Pa. Dezoysa et If. Connerton, THE FUNCTION AND SPECIFICITY OF THE C-TERMINAL TRIPEPTIDE GLYOXYSOMALTARGETING SIGNAL IN NEUROSPORA-CRASSA, Current genetics, 26(5-6), 1994, pp. 430-437
The function of the C-terminal tripeptide targeting signal responsible
for microbody targeting in many eukaryotes has been investigated in t
he filamentous fungus Neurospora crassa. Using an in-vivo targeting as
say that employs transformants carrying C-terminally-modified versions
of the bacterial enzyme chloramphenicol acetyltransferase (CAT), it h
as been demonstrated that C-terminal tripeptide-dependent import occur
s most efficiently in response to nutritional acetate-induction. Under
these conditions Neurospora generates a specialized organelle, the gl
yoxysome, which carries the enzymes responsible for the glyoxylate cyc
le and can be distinguished from peroxisome-like microbodies that cont
ain catalase. Moreover, several C-terminal peptides have been tested i
n this system to extend the tripeptide targeting consensus to A/C/G/S-
H/K/Q/R-I/L/V. However, the tripeptide analogue, ARM, found at the C-t
erminus of the glyoxylate cycle enzyme isocitrate lyase in higher plan
ts, does not apparently function here.