Signal Transduction Overview

Principles

Definition

Signal transduction is the biological process by which a cell converts an external stimulus or signal into a specific cellular response. It involves a series of molecular events, often mediated by receptors and intracellular messengers, that relay and amplify the signal to effect changes in cellular behavior, gene expression, or function, enabling cells to communicate and adapt to their environment.

Ontological type

Key Pathways

Receptor Classes

Second Messengers

Key developments

Key Figures

Calcium-Lipid Second Messengers era

Yoshimi Takai [1] was active at the National Institute for Basic Biology [3] and the University of Washington [4] during this era. His key contributions include Activation of calcium and phospholipid-dependent protein kinase by diacylglycerol, its possible relation to phosphatidylinositol turnover [6], and Calcium-activated, phospholipid-dependent protein kinase from rat brain, Subcellular distribution, purification, and properties [7], which together advanced the understanding of how calcium signals and lipid-derived second messengers regulate kinase activity in this era. Philip Cohen [2] was affiliated with the University of Washington [4] and Cornell University [5] during this era. He defined the subunit structure of rabbit skeletal muscle phosphorylase kinase and the molecular basis of its activation [8], and identified the Ca2+-dependent modulator protein as the fourth subunit of rabbit skeletal muscle phosphorylase kinase [9], contributions that clarified multisubunit kinase architecture and isoform-specific regulation in signaling networks.

Kinase Decision Networks era

Roger J. Davis [1] is a prominent researcher in signal transduction during the Kinase Decision Networks era, with affiliations at Harvard University [3] and the University of California, San Francisco [4]. His key contributions include the Opposing Effects of ERK and JNK-p38 MAP Kinases on Apoptosis [7], the Independent Human MAP-Kinase Signal Transduction Pathways Defined by MEK and MKK Isoforms [8], and the Differential Activation of ERK and JNK Mitogen-Activated Protein Kinases by Raf-1 and MEKK [9], which advanced understanding of modular kinase decision networks and context-dependent survival signaling in this era. Xiaodong Wang [2] is a key contributor to the era, with affiliations at The University of Texas Southwestern Medical Center [5] and the University of Pennsylvania [6]. His landmark Cytochrome c and dATP-Dependent Formation of Apaf-1/Caspase-9 Complex Initiates an Apoptotic Protease Cascade [10] illuminated how mitochondrial state interfaces with caspase execution in kinase-driven cell fate decisions.

mTOR and Immunometabolic Hub era

Terje Johansen [1], with affiliations at Washtenaw Community College [3] and Goethe University Frankfurt [4], figures prominently in the mTOR-immunometabolic hub discourse of this era. Johansen [1] contributed to the understanding of selective autophagy through p62/SQSTM1 [6] binding to Atg8/LC3 [6], enabling degradation of ubiquitinated protein aggregates [6] and thereby connecting proteostasis with nutrient-sensing pathways central to mTOR-driven metabolism. Andreas Brech [2], from University of Oslo [5], co-authored the same 2007 autophagy study on p62/SQSTM1 [6] binding to Atg8/LC3 [6], underscoring a mechanism by which selective autophagy interfaces with metabolic signaling. This work linked ubiquitin-dependent autophagy to nutrient sensing and energy regulation within mTOR-centered immunometabolic hubs [6].