Human liver phosphatase 2A: cDNA and amino acid sequence of two catalytic subunit isotypes

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Biochemistry and Molecular Pharmacology

Publication Date


Document Type



Life Sciences | Medicine and Health Sciences


Two cDNA clones were isolated from a human liver library that encode two phosphatase 2A catalytic subunits. The two cDNAs differed in eight amino acids (97% identity) with three nonconservative substitutions. All of the amino acid substitutions were clustered in the amino-terminal domain of the protein. Amino acid sequence of one human liver clone (HL-14) was identical to the rabbit skeletal muscle phosphatase 2A cDNA (with 97% nucleotide identity). The second human liver clone (HL-1) is encoded by a separate gene, and RNA gel blot analysis indicates that both mRNAs are expressed similarly in several human clonal cell lines. Sequence comparison with phosphatase 1 and 2A indicates highly divergent amino acid sequences at the amino and carboxyl termini of the proteins and identifies six highly conserved regions between the two proteins that are predicted to be important for phosphatase enzymatic activity.

DOI of Published Version



Proc Natl Acad Sci U S A. 1988 Jun;85(12):4252-6.

Journal/Book/Conference Title

Proceedings of the National Academy of Sciences of the United States of America

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Link to article in PubMed

PubMed ID