Generating Diversity and Specificity through Developmental Cell Signaling

摘要: Abstract Highly conserved cell-cell signaling pathways are used reiteratively during development to instruct cellular proliferation, survival, migration, patterning, and differentiation. Responses dependent on spatial temporal context. Related proteins have become functionally specialized evolution. For instance, members of the receptor tyrosine kinase (RTK) superfamily transduce distinct signals, different transforming growth factor (TGF)β family ligands act as activators or inhibitors with diffusion characteristics. Cytoplasmic extensions facilitate some interactions development. In vertebrates, signals received transduced via microtubule-based primary cilia, in Drosophila , filopodia-like cytonemes bearing receptors extend toward sources. Extracellular gradients guide cell migration positional identity patterning many developmental contexts. Multiple strategies employed establish and/or maintain these gradients, including regulatory proteins, use accessory for transport local activation regulated secretion, degradation, recycling receptors, localized stabilization/retention heparin sulfate proteoglycans (HSPGs) membrane localization motifs. can generate responses through signal transduction transcriptional regulation mechanisms. These include protein modifications feedback sensitive thresholds, gene networks, enhancers affinities signal-activated transcription factors (TFs). Different types coordinately in vivo regulators, genes/proteins involved general processes. addition, crosstalk between commonly occurs co-regulation common target genes. Co-regulation genes be mediated by changes chromatin, TFs, coordinate TF activity (e.g., phosphorylation sequestration), enhancer elements.