title: CMP substitutions preferentially inhibit polysialic acid synthesis.
abstract: It is widely reported that derivatives of sugar moieties can be used to metabolically label cell surface carbohydrates or inhibit a particular glycosylation. However, few studies address the effect of substitution of the cytidylmonophosphate (CMP) portion on sialyltransferase activities. Here we first synthesized 2'-O-methyl CMP and 5-methyl CMP and then asked if these CMP derivatives are recognized by alpha2,3-sialyltransferases (ST3Gal-III and ST3Gal-IV), alpha2,6-sialyltransferase (ST6Gal-I), and alpha2,8-sialyltransferase (ST8Sia-II, ST8Sia-III, and ST8Sia-IV). We found that ST3Gal-III and ST3Gal-IV but not ST6Gal-I was inhibited by 2'-O-methyl CMP as potently as by CMP, while ST3Gal-III, ST3Gal-IV, and ST6Gal-I were moderately inhibited by 5-methyl CMP. Previously, it was reported that polysialyltransferase ST8Sia-II but not ST8Sia-IV was inhibited by CMP N-butylneuraminic acid. We found that ST8Sia-IV as well as ST8Sia-II and ST8Sia-III are inhibited by 2'-O-methyl CMP as robustly as by CMP and moderately by 5-methyl CMP. Moreover, the addition of CMP, 2'-O-methyl CMP, and 5-methyl CMP to the culture medium resulted in the decrease of polysialic acid expression on the cell surface and NCAM of Chinese hamster ovary cells. These results suggest that 2'-O-methyl CMP and 5-methyl CMP can be used to preferentially inhibit sialyltransferases, in particular, polysialyltransferases in vitro and in vivo. Such inhibition may be useful to determine the function of a carbohydrate synthesized by a specific sialyltransferase such as polysialyltransferase.
authors: Tumor Microenvironment Program, Glycobiology Unit, Cancer Research Center, Burnham Institute for Medical Research, La Jolla, CA 92037, USA.
authors: Tatsuo
authors: T
authors: Miyazaki
authors: Kiyohiko
authors: K
authors: Angata
authors: Peter H
authors: PH
authors: Seeberger
authors: Ole
authors: O
authors: Hindsgaul
authors: Minoru
authors: M
authors: Fukuda
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D003568:Cytidine Monophosphate / Q000031:analogs & derivatives* / Q000737:chemistry; D005434:Flow Cytometry; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D012794:Sialic Acids / Q000096:biosynthesis*; D012799:Sialyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase
chemical_list: C527664:2'-O-methylcytidine monophosphate; C527665:5-methylcytidine monophosphate; D011994:Recombinant Proteins; D012794:Sialic Acids; C021319:polysialic acid; D012799:Sialyltransferases; D003568:Cytidine Monophosphate; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase