Xenopus<i>laevis</i>Serum Albumin: Sequence of the Complementary Deoxyribonucleic Acids Encoding the 68- and 74-Kilodalton Peptides and the Regulation of Albumin Gene Expression by Thyroid Hormone during Development*

Moskaitis, John E.; Sargent, Thomas D.; Smith, Laurens H.; Pastori, Ricardo L.; Schoenberg, Daniel R.

doi:10.1210/mend-3-3-464

Cited by 46 publications

(12 citation statements)

References 30 publications

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“…Isolation and Sequencing of cDNA Clones-The Xenopus liver cDNA library constructed in ZAP I by EcoRI insertion (16) was kindly provided by Dr. Daniel R. Schoenberg (Uniformed Services, University of the Health Sciences, Bethesda, MD). Approximately 160,000 clones of this cDNA library were screened as described previously (13) using as a probe the full-length cDNA encoding rat pancreatic glucokinase (17), which was kindly provided by Dr. M. A. Magnuson; this cDNA was excised from plasmid pGKZ9 by digestion with EcoRI, purified, and labeled with [␣-32 P]dCTP by random priming (18 the selected clones was purified by the boiling lysis method (19), digested with EcoRI, and analyzed by Southern blotting to identify fragments homologous to rat glucokinase.…”

Section: Methodsmentioning

confidence: 99%

Amino Acid Conservation in Animal Glucokinases

Veiga‐da‐Cunha¹,

Courtois²,

Michel

et al. 1996

Journal of Biological Chemistry

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To delineate the regions of liver glucokinase that are involved in the binding of its regulatory protein and have therefore been conserved throughout evolution, we have cloned the cDNA of the Xenopus laevis enzyme. It contains an open reading frame of 1374 nucleotides and encodes a protein of 458 amino acids, which displays 78 and 79% overall identity to rat and human liver glucokinases, respectively. The conserved regions are predicted to be present mainly in the small domain and the hinge region of glueokinase, and the nonconserved regions in the large domain of the enzyme. We constructed five mutants of Xenopus glucokinase by replacing sets of 2-5 glucokinase-specific residues with their counterparts in the C-terminal half of rat hexokinase I. The affinity for the regulatory protein was not markedly changed for mutants B, D, and E despite a decreased affinity for glucose in mutants B and D. Two other mutants (A and C) were 9- and 250-fold less sensitive to the rat regulator and 40- and 770-fold less sensitive to the Xenopus regulator, respectively, but presented a normal affinity for glucose. The double mutant (A-C) was completely insensitive to inhibition by the regulatory protein. A control mutant (F), obtained by replacing 3 residues that were not conserved in all glucokinases, had a normal affinity for glucose and for the regulatory protein. The property of glucokinase to be inhibited by palmitoyl-CoA was not affected by the mutations described. It is concluded that His-141 to Leu-144, which are located close to the tip of the small domain, as well as Glu-51 and Glu-52, which are present in the large domain of the enzyme close to the hinge region, or nearby residues participate in the binding of the regulatory protein.

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Section: Methodsmentioning

confidence: 99%

Amino Acid Conservation in Animal Glucokinases

Veiga‐da‐Cunha¹,

Courtois²,

Michel

et al. 1996

Journal of Biological Chemistry

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“…Therefore, in order to make a meaningful comparison in evolutionary Table 3. An additional point at 30 Myr is that for the duplicated Xenopus albumins (Bisbee et al, 1977;Moskaitis et al, 1989); the distance was 11.04%. Divergence dates of species within a single mammalian order are as described in the text.…”

Section: How Reliable Is the Clock?mentioning

confidence: 99%

The Molecular Clock Runs at Different Rates Among Closely Related Members of a Gene Family

1998

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The serum albumin gene family is composed of four members that have arisen by a series of duplications from a common ancestor. From sequence differences between members of the gene family, we infer that a gene duplication some 580 Myr ago gave rise to the vitamin D-binding protein (DBP) gene and a second lineage, which reduplicated about 295 Myr ago to give the albumin (ALB) gene and a common precursor to alpha-fetoprotein (AFP) and alpha-albumin (ALF). This precursor itself duplicated about 250 Myr ago, giving rise to the youngest family members, AFP and ALF. It should be possible to correlate these dates with the phylogenetic distribution of members of the gene family among different species. All four genes are found in mammals, but AFP and ALF are not found in amphibia, which diverged from reptiles about 360 Myr ago, before the divergence of the AFP-ALF progenitor from albumin. Although individual family members display an approximate clock-like evolution, there are significant deviations-the rates of divergence for AFP differ by a factor of 7, the rates for ALB differ by a factor of 2.1. Since the progenitor of this gene family itself arose by triplication of a smaller gene, the rates of evolution of individual domains were also calculated and were shown to vary within and between family members. The great variation in the rates of the molecular clock raises questions concerning whether it can be used to infer evolutionary time from contemporary sequence differences.

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“…The Xenopus liver cDNA library constructed in AZAP I (Moskaitis et al, 1989) was kindly provided by Dr Daniel R. Schoenberg from the Uniformed Services University of the Health Sciences. Approximately 100000 clones of this cDNA library, with a phage titre of lo9 plaque-forming units .…”

Section: Isolation and Sequencing Of Cdna Clonesmentioning

confidence: 99%

Cloning and Expression of a Xenopus Liver cDNA Encoding a Fructose‐Phosphate‐Insensitive Regulatory Protein of Glucokinase

Veiga‐da‐Cunha¹,

Detheux²,

Watelet³

et al. 1994

European Journal of Biochemistry

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Xenopus liver contains a protein inhibitor of glucokinase that, in contrast to the mammalian regulatory protein of glucokinase, is insensitive to fructose 6-phosphate and fructose 1 -phosphate [Vandercammen A. & Van Schaftingen, E. (1993) Biochem. J. 294, 551 -5561. The purpose of this work was to compare the primary structure and other properties of this Xenopus protein with those of its rat liver counterpart. A Xenopus laevis liver cDNA library was screened using the cDNA encoding the rat liver regulatory protein as a probe. The cloned cDNA was 2534 bp long and encoded a 619-amino-acid protein with a molecular mass of 68695 Da and 57% identity with the rat liver regulatory protein. This identity was only about 30% in an internal region (amino acids 349-381) and in the 70 carboxy terminal-residues. The Xenopus cDNA was expressed in Escherichia coli and the recombinant regulatory protein was purified to near homogeneity and found to have the same size, reactivity to antibodies and effects on the kinetics of glucokinase as the protein purified from Xenopus liver. In contrast to the rat liver regulatory protein, both recombinant and native Xenopus regulatory proteins were insensitive to fructose 6-phosphate, fructose 1-phosphate and to physiological concentrations of Pi, and they inhibited Xenopus glucolunase with greater affinity than rat glucokinase. These results allow one to conclude that the fructose-phosphate-insensitive protein of lower vertebrates is homologous to the fructose-6-phosphate-sensitive and fructose-1-phosphate-sensitive protein found in mammals.The liver of the rat contains a regulatory protein, also called regulator, which inhibits glucokinase competitively with respect to glucose . Fructose 6-phosphate and fructose 1-phosphate are ligands of this regulatory protein and act competitively, fructose 6-phosphate to reinforce the inhibition, and fructose 1-phosphate to antagonize it. In addition, C1-and other monovalent anions reduce the inhibition exerted by the regulatory protein noncompetitively with respect to fructose 6-phosphate. The presence of the regulatory protein in rat liver explains the activating effect of fructose (Van Schaftingen and Vandercammen, 1989;Davies et al., 1990) and of a potassium-rich medium on the phosphorylation of glucose in isolated hepatocytes. The cDNA encoding the rat liver regulatory protein has been recently cloned (Detheux et al., 1993).A fructose-6-phosphate-sensitive and fructose-l-phosphate-sensitive regulatory protein appears to be present in the livers of all mammalian species that express hepatic glucokinase, including man (Vandercammen and Van Schaftingen, 1993). The livers of the amphibians Bufo marinus and Xenopus laevis, and of the turtle Pseudemys scripta elegans con- tain a protein that inhibits glucokinase competitively with respect to glucose but is insensitive to fructose 6-phosphate and fructose 1-phosphate (Vandercammen and Van Schaftingen, 1993). It was of interest to know if this form of regulatory protein of glucokinase was homologous to ...

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XenopuslaevisSerum Albumin: Sequence of the Complementary Deoxyribonucleic Acids Encoding the 68- and 74-Kilodalton Peptides and the Regulation of Albumin Gene Expression by Thyroid Hormone during Development*

Cited by 46 publications

References 30 publications

Amino Acid Conservation in Animal Glucokinases

Amino Acid Conservation in Animal Glucokinases

The Molecular Clock Runs at Different Rates Among Closely Related Members of a Gene Family

Cloning and Expression of a Xenopus Liver cDNA Encoding a Fructose‐Phosphate‐Insensitive Regulatory Protein of Glucokinase

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