Biomaterial Database

A dynamic complex of signaling proteins uses polar localization to regulate cell-fate asymmetry in Caulobacter crescentus. 2011

Christos G Tsokos, and Barrett S Perchuk, and Michael T Laub

Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Cellular asymmetry is critical to metazoan development and the life cycle of many microbes. In Caulobacter, cell cycle progression and the formation of asymmetric daughter cells depend on the polarly-localized histidine kinase CckA. How CckA is regulated and why activity depends on localization are unknown. Here, we demonstrate that the unorthodox kinase DivL promotes CckA activity and that the phosphorylated regulator DivK inhibits CckA by binding to DivL. Early in the cell cycle, CckA is activated by the dephosphorylation of DivK throughout the cell. However, in later stages, when phosphorylated DivK levels are high, CckA activation relies on polar localization with a DivK phosphatase. Localization thus creates a protected zone for CckA within the cell, without the use of membrane-enclosed compartments. Our results reveal the mechanisms by which CckA is regulated in a cell-type-dependent manner. More generally, our findings reveal how cells exploit subcellular localization to orchestrate sophisticated regulatory processes.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D011494	Protein Kinases	A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.	Protein Kinase,Kinase, Protein,Kinases, Protein
D011993	Recombinant Fusion Proteins	Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.	Fusion Proteins, Recombinant,Recombinant Chimeric Protein,Recombinant Fusion Protein,Recombinant Hybrid Protein,Chimeric Proteins, Recombinant,Hybrid Proteins, Recombinant,Recombinant Chimeric Proteins,Recombinant Hybrid Proteins,Chimeric Protein, Recombinant,Fusion Protein, Recombinant,Hybrid Protein, Recombinant,Protein, Recombinant Chimeric,Protein, Recombinant Fusion,Protein, Recombinant Hybrid,Proteins, Recombinant Chimeric,Proteins, Recombinant Fusion,Proteins, Recombinant Hybrid
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D004843	Epistasis, Genetic	A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.	Deviation, Epistatic,Epistatic Deviation,Genes, Epistatic,Genes, Hypostatic,Epistases, Genetic,Gene-Gene Interaction, Epistatic,Gene-Gene Interactions, Epistatic,Genetic Epistases,Genetic Epistasis,Interaction Deviation,Non-Allelic Gene Interactions,Epistatic Gene,Epistatic Gene-Gene Interaction,Epistatic Gene-Gene Interactions,Epistatic Genes,Gene Gene Interaction, Epistatic,Gene Gene Interactions, Epistatic,Gene Interaction, Non-Allelic,Gene Interactions, Non-Allelic,Gene, Epistatic,Gene, Hypostatic,Hypostatic Gene,Hypostatic Genes,Interaction, Epistatic Gene-Gene,Interaction, Non-Allelic Gene,Interactions, Epistatic Gene-Gene,Interactions, Non-Allelic Gene,Non Allelic Gene Interactions,Non-Allelic Gene Interaction
D000071677	Histidine Kinase	A member of the transferase superfamily of proteins. In the activated state, protein-histidine kinase autophosphorylates at a histidine residue, subsequently transferring high-energy phosphoryl groups to an aspartate residue of the response-regulator domain, which results in a conformational shift in the effector domain. Histidine kinases mediate signal transduction in a wide range of processes involving cellular adaptation to environmental stress.	Histidine Protein Kinase,Histone H4 Histidine Kinase,Protein Histidine Pros-Kinase,Protein Kinase (Histidine), Pros-Kinase,Protein-Histidine Kinase,Protein-Histidine Pros-Kinase,Protein-Histidine Tele-Kinase,Sensor Histidine Kinase,Histidine Kinase, Sensor,Histidine Pros-Kinase, Protein,Kinase, Histidine,Kinase, Histidine Protein,Kinase, Protein-Histidine,Kinase, Sensor Histidine,Pros-Kinase, Protein Histidine,Pros-Kinase, Protein-Histidine,Protein Histidine Kinase,Protein Histidine Pros Kinase,Protein Histidine Tele Kinase,Protein Kinase, Histidine,Tele-Kinase, Protein-Histidine
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D015398	Signal Transduction	The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.	Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal
D016764	Cell Polarity	Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.	Cell Polarities,Polarities, Cell,Polarity, Cell