The search for a functional thrombin receptor, using expression cloning methods, led to the discovery of a G protein-coupled receptor that mediates the actions of thrombin on platelets and endothelial cells.
Cyclin dependent kinases (CDKs) are typical serine/threonine kinases that display the 11 subdomains shared by all kinases. The complete sequence of the Homo sapiens genome shows that among the ~30,000 predicted genes, there are 13 CDKs and 25 cyclins. Eleven
Troponin together with tropomyosin, regulate the binding of myosin to actin. Troponin is a trimeric protein composed of Troponin subunits I, C and T. Troponin C binds calcium ions, Troponin T binds to tropomyosin and troponin I binds
The amount of cholesterol that is synthesized in the liver is tightly regulated by dietary cholesterol levels. LDL receptors regulate the cellular transport of lipid rich low density lipoprotein (LDL) particles.
Adenylyl cyclases occur throughout the animal kingdom and play diverse roles in cell regulation. In bacteria, the enzyme may be regulated in response to nutrients or it may constitute a toxic factor in mammals, as with adenylyl cyclases of B.
Muscarinic acetylcholine receptors are G protein-coupled receptors (GPCRs) and mediate acetylcholine actions in the CNS and non-nervous tissues. Learn more about acetylcholine receptors and their role in cell signaling.
Tec kinases represent the second largest family of nonreceptor tyrosine kinases and are activated in response to cellular stimulation by antigen receptors, integrins, growth factors, cytokines and G protein-coupled receptors.
Ryanodine and InsP3 receptors share both structural and functional characteristics. Both receptor families are made up of subunits that are among the largest of known proteins and for each the functional channel comprises a tetramer in which six membrane-spanning helices
The hydrolysis of a minor membrane phospholipid, phosphatidylinositol 4,5-bisphosphate (PIP2) by a specific phospholipase C (PLC) is one of the earliest key events in the regulation of various cell functions by more than 100 extracellular signaling molecules.
Heterotrimeric G proteins, comprising α, β and γ subunits, respond to extracellular signals generated by activated seven-transmembrane (7TM) receptors by modulating intracellular effector proteins such as enzymes and ion channels.
Glutamine is a common precursor for the biosynthesis of both glutamate and GABA. Glutamine can be transported in and out of neurons and astrocytes utilizing different glutamine carriers. The neurotransmitter glutamate can be synthesized from glutamine by the action of
Dopamine-β-hydroxylase is located inside amine storage vesicles of norepinephrine neurons. Dopamine is actively transported from the cytoplasm into the vesicles. As the enzyme is a copper containing protein, its activity can be inhibited by copper chelating agents, such as diethyldithiocarbamate