Contents
XVII
CHAPTER
26
Regulation of Gene Expression
26.1
Regulation of mRNA
593
26.2
Gene Regulation in Prokaryotes
594
Lactose (lac) Operon
594
Tryptophan (trp) Operon
595
Temporal mRNA Regulation in Phage
Systems
598
Régulons
599
26.3
Gene Regulation in Eukaryotes
599
Housekeeping Genes and RNases
600
Gene Families
600
26.4
Mechanisms of Gene Regulation in
Eukaryotes
601
Transcription Factors
601
Steroid Receptors
603
G-Protein Diseases
604
Regulation of Transcription by Méthylation
604
Genomic Imprinting
606
Regulation of RNA Processing
606
Alternative RNA Splicing and Editing
607
Regulation of Iron Utilization in Cells
607
Polyproteins
608
Translational Regulation
608
Regulation of Protein Activity
608
26.5
Regulation of Cell Death: Apoptosis
609
26.6
Regulation of Cell Proliferation:
Oncogenes
609
26.7
Retroviruses and AIDS
612
Supplemental Readings
and References
613
CHAPTER
27
Nucleotide Metabolism
27.1
One-Carbon Metabolism
615
Inhibitors of Dihydrofolate Reductase
617
Formation of One-Carbon Derivatives
of Folate
617
27.2
Formation of
5-Phosphoribosyl-1-Pyrophosphate
619
27.3
Biosynthesis of Purine Nucleotides
620
De Novo
Synthesis
620
Salvage Pathways
622
Dietary Purines
623
27.4
Conversion of Nucleoside Monophosphates
to Diphosphates and Triphosphates
624
27.5
Formation of Purine
Deoxyribonucleotides
624
27.6
Regulation of Purine Biosynthesis
625
PRPP Synthetase Reaction
625
Amidophosphoribosyltransferase Reaction
625
Regulation of Formation of AMP and GMP
from IMP
626
27.7
Inhibitors of Purine Biosynthesis
626
Inhibitors of Folate Biosynthesis
626
Inhibitors of Formation of IMP
626
Inhibitors of Formation of AMP and GMP
626
Inhibitors of Multiple Steps—Purine
Analogues
627
Inhibition of Conversion of Ribonucleoside
Diphosphate to Deoxyribonucleoside
Diphosphate
628
27.8
Catabolism of Purine Nucleotides
628
Xanthine Oxidase Reaction
629
Disorders of Purine Nucleotide Metabolism
630
Gout
630
Overproduction of PRPP
631
Treatment
631
Dietary and Lifestyle Factors
633
Lesch-Nyhan Syndrome
633
Adenine Phosphoribosyltransferase (APRT)
Deficiency
634
Adenosine Deaminase (ADA) Deficiency and
Purine Nucleoside Phosphorylase (PNP)
Deficiency
634
Myoadenylate Deaminase Deficiency
636
Xanthine Oxidase Deficiency
637
