Open AccessSequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.
Author(s) -
Christopher B. Newgard,
Kenichi Nakano,
Peter K. Hwang,
Robert J. Fletterick
Publication year - 1986
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.83.21.8132
Subject(s) - complementary dna , biology , glycogen phosphorylase , microbiology and biotechnology , nucleic acid sequence , peptide sequence , biochemistry , messenger rna , start codon , glycogen , gene
We have cloned the cDNA encoding glycogen phosphorylase (1,4-alpha-D-glucan:orthophosphate alpha-D-glucosyl-transferase, EC 2.4.1.1) from human liver. Blot-hybridization analysis using a large fragment of the cDNA to probe mRNA from rabbit brain, muscle, and liver tissues shows preferential hybridization to liver RNA. Determination of the entire nucleotide sequence of the liver message has allowed a comparison with the previously determined rabbit muscle phosphorylase sequence. Despite an amino acid identity of 80%, the two cDNAs exhibit a remarkable divergence in G+C content. In the muscle phosphorylase sequence, 86% of the nucleotides at the third codon position are either deoxyguanosine or deoxycytidine residues, while in the liver homolog the figure is only 60%, resulting in a strikingly different pattern of codon usage throughout most of the sequence. The liver phosphorylase cDNA appears to represent an evolutionary mosaic; the segment encoding the N-terminal 80 amino acids contains greater than 90% G+C at the third codon position. A survey of other published mammalian cDNA sequences reveals that the data for liver and muscle phosphorylases reflects a bias in codon usage patterns in liver and muscle coding sequences in general.