Quantitation of muscle glycogen phosphorylase mRNA and enzyme amounts in adult rat tissues

David, Emina S.; Crerar, Michael M.

doi:10.1016/0304-4165(86)90122-4

Cited by 62 publications

(46 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The three isozymes are tissue-specific; the brain type (also known as the fetal type) is predominant in adult brain and embryonic tissues, while the liver and muscle types are predominant in adult liver and skeletal muscle tissues, respectively (reviewed in ref. 4). The muscle form is the best characterized; both the primary sequence and the x-ray structure of rabbit muscle phosphorylase are known (5)(6)(7)(8).…”

mentioning

confidence: 99%

“…The enzyme functions in muscle to provide glucose required for the energy of contraction. Its physiological role is distinct from the liver isozyme, which is centrally involved in the maintenance of blood glucose homeostasis, and from the brain form, which is associated primarily with provision of an emergency glucose supply during brief periods of anoxia or hypoglycemia (4,9).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.

Newgard¹,

Nakano²,

Hwang³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We have cloned the cD)NA encoding glycogen phosphorylase (1,4-a-D-glucan:orthophosphate a-D-glucosyltransferase, 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 qucleotide 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 >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.Glycogen phosphorylase (1,4-a-D-glucan:orthophosphate a-D-glucosyltransferase, EC 2.4.1.1) isozymes play a vital role in mobilization of stored sugar in a variety of mammalian tissues. Three forms of the enzyme have been described that are distinguished by their electrophoretic mobilities on gels and their immunological properties (1-3). The three isozymes are tissue-specific; the brain type (also known as the fetal type) is predominant in adult brain and embryonic tissues, while the liver and muscle types are predominant in adult liver and skeletal muscle tissues, respectively (reviewed in ref. 4). The muscle form is the best characterized; both the primary sequence and the x-ray structure of rabbit muscle phosphorylase are known (5-8). The enzyme functions in muscle to provide glucose required for the energy of contraction. Its physiological role is distinct from the liver isozyme, which is centrally involved in the maintenance of blood glucose homeostasis, and from the brain form, which is associated primarily with provision of an emergency glucose supply during brief periods of anoxia or hypoglycemia (4, 9).Comparisons of the protein and DNA sequences of the phosphorylase isozymes are required to understand the evolutionary and functional relationships among them. Further, such comparisons could ultimately provide insight into how the phosphorylase genes, and perhaps other multigene families, are regulated in a developmental and tissue-specific manner. We have described the cloning and sequencing ofthe rabbit muscle glycogen phosphorylase cDNA and portions of the C-terminal domain from human and rat muscle (6, 7). We report here the cDNA sequence and the deduced amino acid sequence for human liver glycogen phosphorylase. Comparison of liver and muscle phosphorylase sequences reveals extensive...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.

Newgard¹,

Nakano²,

Hwang³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The muscle form is best characterized; it provides energy for muscle contraction. Its physiological role is distinct from that of the liver isoenzyme, which plays a central role in the maintenance of blood glucose homoeostasis, and from the brain form, which is involved in the provision of an emergency glucose supply during periods of anoxia and hypoglycaemia [13][14][15][16][17]. Phosphorylase isoenzymes exhibit differences in regulatory properties that may be related to their distinct physiological roles, especially with regard to their response to the allosteric ligand AMP [11,18,19], which is high for the muscle but low for the liver isoenzyme.…”

Section: Introductionmentioning

confidence: 99%

“…Mammalian glycogen phosphorylases were found in at least three isoenzymic forms that could be distinguished by structural and functional properties [8][9][10][11][12][13][14]. In the rat, the brain form has been shown to be the predominant isoenzyme in fetal tissues and in many adult organs.…”

Section: Introductionmentioning

confidence: 99%

Glycogen phosphorylase isoenzymes from hepatoma 3924A and from a non-tumorigenic liver cell line. Comparison with the liver and brain enzymes

Mayer

Seelmann-Eggebert

Letsch

1992

Biochemical Journal

View full text Add to dashboard Cite

Glycogen phosphorylase isoenzymes were isolated from normal rat liver, rat brain, the glycogen-poor Morris hepatoma (MH) 3924A, and the glycogen-rich non-tumorigenic liver cell line C1I. Electrophoretic and immunological characterization of the enzymes showed that tumour and C1I cells expressed a phosphorylase isoform similar to the brain type; the liver type was not detectable. All enzymes were obtained as dimers; the Mr of the subunits was 96000 (liver), 93000 (brain and MH 3924A) and 92000 (C1I). Isoelectric focusing revealed a main band of pI 6.34 for liver phosphorylase a, pl 5.67 for the enzymes from MH 3924A and brain, and pI 5.68 for CII phosphorylase. Partial kinetic characterization of the AMP-independent forms of the isoenzymes yielded Km values for glucose 1-phosphate of 3.5 + 0.5 mm (liver), 3.9 mm (brain), 1.9 + 0.3 mm (MH 3924A) and 2.5 + 0.5 mm (C1I); Km values for glycogen were 0.4 mM (liver) and 0.3 mm (MH 3924A and C1I), calculated as glucose equivalents. The AMP-independent phosphorylase was inhibited by glucose 6-phosphate (Glc6P) with Ki values of 0.32 + 0.03 mm (C1I), 0.50 + 0.04 mm (MH 3924A) and -5 mM (brain). The inhibition could be abolished by 1 mM-AMP, indicating that AMP and Glc6P may partially compete for the same site on the protein. Liver phosphorylase a was not inhibited by up to 25 mM-Glc6P. In contrast with liver and brain isoenzymes, phosphorylase from the cell lines was not affected by NaF and Na2SO4. The data show that both the hepatocellular carcinoma and the non-malignant immortalized liver cells express a phosphorylase isoform different from the liver type. Furthermore, there is some evidence that the enzyme from MH 3924A and C1I cells is distinct from brain phosphorylase a, in spite of electrophoretic and immunological resemblance, and that this isoenzyme is subject to altered metabolic regulation.

show abstract

“…Zhao et al (1995) reported a 20% coefficient of variation when quantifying matrix Gla protein mRNA by QC-RT-PCR after normalization to GAPDH mRNA levels, although only 3 independent RNA samples from cultured normal rat kidney cells were measured. David and Crerar (1986) found a 21% coefficient of variation in muscle glycogen phosphorylase protein levels taken from skeletal muscle samples of 5 to 7 rats and that muscle glycogen phosphorylase mRNA levels, as measured by Northern blot analysis, showed a 27% coefficient of variation from 3 separate skeletal muscle RNA preparations. All of these experimental analyses are consistent with an approximate 24% coefficient of variation when measuring the expression level of any one specific gene in a simple biological sample.…”

Section: Discussionmentioning

confidence: 99%

Determination of variations in gene expression during fracture healing

Balaburski

O’Connor

2003

Acta Orthopaedica Scandinavica

View full text Add to dashboard Cite

Quantitation of muscle glycogen phosphorylase mRNA and enzyme amounts in adult rat tissues

Cited by 62 publications

References 35 publications

Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.

Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.

Glycogen phosphorylase isoenzymes from hepatoma 3924A and from a non-tumorigenic liver cell line. Comparison with the liver and brain enzymes

Determination of variations in gene expression during fracture healing

Contact Info

Product

Resources

About