UDP-glucose deficiency in a mutant cell line protects against glucosyltransferase toxins from Clostridium difficile and Clostridium sordellii.
We have previously isolated a fibroblast mutant cell with high resistance to the two Rho-modifying glucosyltransferase toxins A and B of Clostridium difficile. We demonstrate here a low level of UDP-glucose in the mutant, which explains its toxin resistance since: (i) to obtain a detectable toxin B-mediated Rho modification in lysates of mutant cells, addition of UDP-glucose was required, and it promoted the Rho modification dose-dependently; (ii) high pressure liquid chromatography analysis of nucleotide extracts of cells indicated that the level of UDP-glucose in the mutant (0.8 nmol/10(6) cells) was lower than in the wild type (3.7 nmol/10(6) cells); and (iii) sensitivity to toxin B was restored upon microinjection of UDP-glucose. Using the mutant as indicator cell we also found that the related Clostridium sordellii lethal toxin is a glucosyltransferase which requires UDP-glucose as a cofactor. Like toxin B it glucosylated 21-23-kDa proteins in cell lysates, but Rho was not a substrate for lethal toxin.
Chaves-Olarte
E
E
Microbiology & Tumorbiology Center (MTC), Box 280, Karolinska Institute, S-171 77 Stockholm, Sweden.
Florin
I
I
Boquet
P
P
Popoff
M
M
von Eichel-Streiber
C
C
Thelestam
M
M
D000818:Animals; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000633:toxicity*; D002460:Cell Line; D016360:Clostridioides difficile / Q000378:metabolism*; D003013:Clostridium / Q000378:metabolism*; D006224:Cricetinae; D003412:Cricetulus; D019204:GTP-Binding Proteins / Q000378:metabolism; D005964:Glucosyltransferases / Q000633:toxicity*; D008845:Microinjections; D009154:Mutation; D014532:Uridine Diphosphate Glucose / Q000172:deficiency*
D001426:Bacterial Proteins; D001427:Bacterial Toxins; C072292:lethal toxin LT, Clostridium sordellii; C031815:toxB protein, Clostridium difficile; D005964:Glucosyltransferases; D019204:GTP-Binding Proteins; D014532:Uridine Diphosphate Glucose