. "Catalysis of the reaction: UDP-glucose + ((1,4)-beta-D-glucosyl)(n) = UDP + ((1,4)-beta-D-glucosyl)(n+1)." . . . "cellulose synthase (UDP-forming) activity" . "1,4-beta-D-glucan synthase activity" . "1,4-beta-glucan synthase activity" . "beta-1,4-glucan synthase activity" . "beta-1,4-glucan synthetase activity" . "beta-1,4-glucosyltransferase activity" . "beta-glucan synthase activity" . "glucan synthase activity" . "GS-I" . "UDP-glucose-1,4-beta-glucan glucosyltransferase activity" . "UDP-glucose-beta-D-glucan glucosyltransferase activity" . "UDP-glucose-cellulose glucosyltransferase activity" . "UDP-glucose:1,4-beta-D-glucan 4-beta-D-glucosyltransferase activity" . "UDPglucose-beta-glucan glucosyltransferase activity" . "UDPglucose-cellulose glucosyltransferase activity" . "UDPglucose:1,4-beta-D-glucan 4-beta-D-glucosyltransferase activity" . "uridine diphosphoglucose-1,4-beta-glucan glucosyltransferase activity" . "uridine diphosphoglucose-cellulose glucosyltransferase activity" . . .