- Dynamic signal processing by MAPK pathways
Recent studies show that MAPK pathways perform exquisite spatial and temporal signal processing. This review discusses the mechanisms that process dynamic inputs into graded output responses, the role of positive and negative feedbacks, and feedforward regulation.
- ARNO-ARF1 signaling controls podosome formation
Rafiq et al. demonstrate that the small G protein ARF1 and its activator, cytohesin 2 (ARNO), are required for podosome formation in macrophage-like cells and fibroblasts. Inhibition of ARNO-ARF1 signaling results in increased RhoA activity and disassembly of podosomes in a myosin-IIA–dependent fashion. In fibroblasts that normally do not form podosomes, constitutively active ARF1 induces actin-rich puncta associated with sites of matrix degradation, putative precursors of podosomes.
- Mammalian synthetic biology
Novel approaches in mammalian synthetic biology are advancing the study of cellular processes, regulatory networks, and multicellular interactions. Mathur et al. describe how the design of sophisticated genetic components supported by quantitative standards and computational tools will continue to expand the impact of synthetic biology on cell biology research.