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Phenylalanine hydroxylase in melanoma cells
Author(s) -
Breakefield Xandra O.,
Castiglione Carmela M.,
Halaban Ruth,
Pawelek John,
Shiman Ross
Publication year - 1978
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040940308
Subject(s) - phenylalanine hydroxylase , phenylalanine , tyrosine hydroxylase , tyrosine , biochemistry , tryptophan hydroxylase , tyrosine 3 monooxygenase , enzyme , chemistry , tyrosinase , tryptophan , antiserum , sodium dodecyl sulfate , microbiology and biotechnology , biology , amino acid , antibody , immunology , receptor , serotonergic , serotonin
A pigmented subclone of Cloudman S91 melanoma cells, PS1‐wild type, can grow in medium lacking tyrosine. This ability is conferred by phenylalanine hydroxylase activity, and not by tryptophan hydroxylase, tyrosine hydroxylase or tyrosinase activities, although the latter activity is also present in these cells. Conversion of phenylalanine to tyrosine was measured in living cells by chromatographic identification of the metabolites of [ 14 C]phenylalanine and in cell extracts using a sensitive assay for phenylalanine hydroxylase. Phenylalanine hydroxylase activity in melanoma cell extracts was identified by its inhibition with p‐chlorophenylalanine and not with 6‐fluorotryptophan, 3‐iodotyrosine, phenylthiourea, tyrosine or tryptophan; and by adsorption with antiserum prepared against purified rat liver phenylalanine hydroxylase, and migration of immunoprecipitable activity with authentic phenylalanine hydroxylase subunits in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis.