The expression of carbohydrate blood group antigens correlates with heat resistance.
Recent data indicate that cells may resist heat shock via more than one route: heat shock protein synthesis and other still ill-defined mechanisms. We investigated this phenomenon using four types of cells derived from a single rat colon carcinoma: clones REGb and PROb; PRO A+, a glycosylation variant of PROb selected for its high expression of blood group A antigen; and Ph8, a thermoresistant variant of PROb selected by repeated sublethal heat treatments. Basal heat resistance was clearly associated with the level of cell surface expression of blood group H and A antigens. Biosynthesis of these carbohydrate structures requires two glycosyltransferases, H and A enzymes, whose activities are also correlated with basal heat resistance. In addition, heat sensitive REGb cells were rendered more resistant by transfection with the gene encoding for H enzyme, allowing expression of H antigen. Thus, these terminal glycosylations could play a role as cellular protectors against heat treatment. Blood group carbohydrate antigens were mainly located on O-linked carbohydrate chains of a major glycoprotein of 200 kDa and to a lesser extent on N-linked chains. Only trace amounts were present as glycolipids.
Ménoret
A
A
INSERM U419, Institut de Biologie, Nantes, France.
Otry
C
C
Labarrière
N
N
Breimer
M E
ME
Piller
F
F
Meflah
K
K
Le Pendu
J
J
D000017:ABO Blood-Group System / Q000096:biosynthesis*; D000230:Adenocarcinoma; D000818:Animals; D002240:Carbohydrate Sequence; D002999:Clone Cells; D003110:Colonic Neoplasms; D015870:Gene Expression; D006017:Glycolipids / Q000032:analysis / Q000096:biosynthesis; D016695:Glycosyltransferases / Q000378:metabolism; D006358:Hot Temperature; D007700:Kinetics; D008969:Molecular Sequence Data; D051381:Rats; D014407:Tumor Cells, Cultured
D000017:ABO Blood-Group System; D006017:Glycolipids; D016695:Glycosyltransferases