Cell Signaling & Neuroscience Hypothetical Model

Slides Programmed Cell Death Activation and Inhibition of Apoptosis Mitochondria in Apoptosis ATM/p53 Signaling Pathway Caspase Cascade Caspase Activation Intrinsic Pathway Granzyme B FAS and Related Proteins Fas Signaling G1, and S Phases G2 and M Phases Regulatory Cascade The p53 Signaling Pathway Cytokines and Growth Factors Structures of Activin and Inhibin Structures of Chemokine Receptors Angiopoietins EGFR Signaling Pathway Transmembrane Precursors of EGF Possible Receptor Combos and Ligand Actions of Flt-3/Flk-2 Hedgehog and BMI1 IGF Regulation of Apoptosis IL-13 and IL-4 receptor IL-18 Production Neurotrophins and Their Receptors TrkA GDNF Family with Receptors PDGF Receptors and Actions TGF-beta Signaling BMP Signaling TNF Signaling TNF-α and TNF-β Proposed Balance Between TNF Superfamily Structure of Receptors VEGF Receptor and Ligands Prolactin Regulation Insulin Pathway Glucocorticoid Receptor Signaling Vascular Endothelial Cell Interactions Integrin Signaling in Cell Survival VEGF Receptor Signaling MMPs and Cytokines Events Leading to Angiogenesis Transcription Factors Nuclear Complex Targeting Jak/Stat Pathway STAT3 PPAR Formation of Nucleosomes DNA Compaction Early Response Events Cell Cycle Checkpoint Linkage between DNA Repair and Chromatin Modification Functions of WRN, BLM and MRE11 mRNP Transport Importinα - Importinβ Pathway Modular Structure of Transcription factors Transcription Activation by Nuclear Receptors Coupled RNA Splicing and Nuclear Export RNA Polyadenylation Mammalian mRNA Polyadenylation RNA Maturation Epigenetic Control Phosphorylation-driven Initiation-Elongation cAMP Metabolism cGMP Metabolism G-Protein Signaling T Cell Receptor B Cell Receptor Monovalent Ion Channels Activation/Inactivation Ligand-Gated Ion Channel Aquaporin Channel Structure Calcium Channel Structure Calcium Channel Pore Region Chloride Channel HCN Channel 2TM Potassium Channel Structure 6TM Potassium Channel Structure Sodium Channel Structure Sodium Channel Pore Region PTEN Pathway Lipids in Cell Signaling Inositol Phosphates Phosphatidic Acid Inositol Phospholipids ABC Transporters ABC-ATPases BSEP MRP1 β-Amyloid Plaques Notch Secretase Second Messenger Systems Limbic Reward Circuit Major Pathways in the CNS Endothelin Signaling NPY and Catecholamines Ascending Pain Pathway Modulation of Pain Transmission Mechanism of Action Fig. A Mechanism of Action Fig. B Drug Activation of Dopaminergic GABAB Receptor Oxidative Stress nNOS eNOS iNOS Nitric Oxide Proteasome/Ubiquitination Formation of Activated 20S Proteasome Ubiquitin Pathway MAP Kinase Cascades AKT Signaling Pathways Activated by VEGF

Hypothetical Model on the Functions of the WRN, BLM and MRE11

WRN and BLM are genes encoding DNA helicases mutated in the human progeria syndromes: Werner and Bloom Syndromes. MRE11 complex is mutated in genetic instability syndromes: Nijmegen breakage syndrome and ataxia telangiectasia-like disorder. All three may be involved in the resolution of a stalled replication fork and in checkpoint signaling during S phase. DNA replication fork stalling results in the formation of abnormal structures and occurs at frequencies sufficient to be a significant source of endogenous DNA damage. BLM may be recruited to these sites resulting in its phosphorylation by ataxia telangiectasia mutated protein-related protein (ATR). The activated or phosphorylated BLM determines the proper recruitment of the MRE11 complex. WRN may be required at this point to provide endonuclease or helicase activity. Also at this stage, WRN may be phosphorylated by ATR or by MRE11 and NBS1, resulting in checkpoint reinforcement. Replication recovery can also involve homologous recombination (HR) and BRCA1 and RAD51.

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