Heterogeneity of alkaline phosphatases in different HeLa lines.
Alkaline phosphatase (ALP) components in 8 cell lines of HeLa were examined. Line to line heterogeneity in ALP expression was observed using the criteria of electrophoretic mobility before and after neuraminidase treatment, heat stability, L-phenylanine inhibition, and reactivity against antiplacental ALP antiserum. Six lines contained a placentallike ALP isozyme and varying amounts of a liverlike ALP isozyme. One line contained a liverlike ALP isozyme only. One line contained a new ALP form which was clearly distinguished from the placental, liver, bone, and intestinal ALPs. Thus, derepression of the placental ALP structural locus appeared to have occurred in 6 of the 8 lines. However, where expressed, the placentallike ALP varied electrophoretically from line to line, and in only one case was the mobility identical to that of a common placental ALP phenotype. This phenotypic heterogeneity of the ""derepressed'' placentallike ALP contrasts markedly with the phenotypic stability of other enzymes expressed in HeLa cells.
D000469:Alkaline Phosphatase / Q000235:genetics*; D002460:Cell Line; D002874:Chromosome Mapping; D006367:HeLa Cells / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D010641:Phenotype; D010920:Placenta / Q000201:enzymology
D007527:Isoenzymes; D000469:Alkaline Phosphatase