Signal Transduction Pathways

Extracellular stimuli (such as growth factors, hormones, and neurotransmitters) provoke cells to change their behavior by expressing a different set of genes in a process known as signal transduction. The binding of ligands to their receptors triggers specific signal transduction pathways. These pathways often activate protein kinase cascades, ultimately activating one or more transcription factors. The activated transcription factors alter the expression of downstream effector genes. Two or more signal transduction pathways often cross-talk via the activation or inhibition of downstream signaling molecules or target genes in common. Such pathway interactions may contribute to the same biological response or phenotype under study. For example, both TGFβ and WNT signaling pathways are important in developmental processes. SMAD1, a TGFβ transcription factor, is phosphorylated by GSK3β and degraded. During canonical WNT signaling, the kinase GSK3β is negatively regulated, promoting TGFβ signaling. In a similar manner, dysregulation of one signaling pathway may affect additional signaling pathways. For example, activation of JAK/STAT signaling can stimulate VEGF signaling, causing increased angiogenesis. However, pathway cross-talk cannot occur if the specific cell type of interest does not express the relevant genes for both signaling pathways. Signal transduction pathway analyses are important to understanding the molecular mechanisms of most biological processes.

QIAGEN provides a broad range of assay technologies for signal transduction pathway research that enables analysis of gene expression and regulation, epigenetic modification, genotyping, and signal transduction pathway activation. Solutions optimized for signal transduction pathway studies include PCR array, miRNA, siRNA, mutation analysis, pathway reporter, chromatin IP, DNA methylation, and protein expression products.