cDNA cloning of a liver isoform of the phosphorylase kinase alpha subunit and mapping of the gene to Xp22.2-p22.1, the region of human X-linked liver glycogenosis.
We have cloned cDNA molecules encoding another isoform of the alpha subunit of phosphorylase kinase (ATP:phosphorylase-b phosphotransferase, EC 2.7.1.38). Sequence comparison with the previously characterized muscle isoform reveals a pattern of highly conserved and variable domains and demonstrates that the isoforms are the products of distinct genes. In contrast to the muscle isoform gene, PHKA1, the gene of this additional isoform, PHKA2, is predominantly expressed in liver and other nonmuscle tissues. It was mapped to the distal short arm of the human X chromosome (Xp22.2-p22.1), the same region to which human X-linked liver glycogenosis due to phosphorylase kinase deficiency has been mapped. Thus, X-linked liver glycogenosis is probably caused by mutations affecting PHKA2.
Institut für Physiologische Chemie, Ruhr-Universität Bochum, Germany.
J J
JJ
Davidson
T
T
Ozçelik
C
C
Hamacher
P J
PJ
Willems
U
U
Francke
M W
MW
Kilimann
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002871:Chromosome Banding; D002874:Chromosome Mapping; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D015723:Gene Library; D005796:Genes; D006008:Glycogen Storage Disease / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D006822:Hybrid Cells; D007527:Isoenzymes / Q000235:genetics*; D008099:Liver / Q000201:enzymology*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology; D009928:Organ Specificity; D010764:Phosphorylase Kinase / Q000235:genetics*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014960:X Chromosome
D007527:Isoenzymes; D046911:Macromolecular Substances; D012333:RNA, Messenger; D012313:RNA; D004247:DNA; D010764:Phosphorylase Kinase