The ether-a-go-go gene (EAG) family is a relative novel group of K+– channels, which belong to an increasing number of …
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Staurosporine and K252a Compounds
Protein phosphorylation constitutes one of the most important molecular mechanisms by which extracellular signals produce their biological responses in eukaryotic cells. Stimulation of protein kinases is considered to be the most common activation mechanism in signal transduction systems1. The protein serine/threonine kinase can be classified by the nature of their second messenger activators:
Continue readingThe Purinergic P2Y Receptors
P2 receptors mediate the actions of the extracellular nucleotides (ATP, ADP, UTP, UDP) and regulate several physiologic responses, among them, cardiac function, platelet aggregation, and SMC proliferation1. The metabotropic P2Y receptors belong to the G-protein-coupled receptor (GPCR) super family. There are currently six functional mammalian P2Y receptors: P2Y1, P2Y2, P2Y4, P2Y6, P2Y11 and P2Y12 which differ in their selectivity for adenine and uracil nucleotides: ATP (P2Y11 receptor), ADP (P2Y1, P2Y12 receptors), UTP (P2Y4 receptor). The response of P2Y4 to ATP is species-dependent. UDP activates the P2Y6 receptor. The P2Y2 receptor is equipotently activated by ATP and UTP. Most P2Y receptors (with the exception of P2Y11 and P2Y12) are coupled to the activation of phospholipase C (PLC), leading to the formation of
Continue readingproNGF and proBDNF: The Alter Egos
Neurotrophins, like many growth factors, are expressed as precursor proteins which are then truncated and further modified to yield the …
Continue readingNGF: One Molecule, Multiple Functions
Nerve Growth Factor (NGF) is one of the founding and best-characterized members of the neurotrophin family. This family comprises a …
Continue readingBDNF – Second Best?
Brain Derived Neurotrophic Factor (BDNF) is the second best characterized neurotrophin (following NGF) and acts as a key contributor to …
Continue readingp75NTR – The Promiscuous Receptor
The p75 neurotrophin receptor (p75NTR) could bind a variety of proteins all with biological significance. While this receptor has no …
Continue readingIon Channels and Tyrosine Kinases
Modulation of ion channel activity is a fundamental mechanism in many tissues. Ion channels, like many other proteins are targets for several intracellular signaling pathways, including protein phosphorylation and dephosphorylation. These processes can modify channel activity and dramatically alter the electrophysiological properties of both excitable and nonexcitable cells1-5. The amino acid sequences of ion channels suggest that many contain a wide variety of possible phosphorlyation sites. Phosphorylation in general and Tyrosine Phosphorylation (TP) in particular were shown to participate in the control of ion channel activity. Initial evidence showing that ion channels may be regulated by TP came largely from pharmacological studies using soluble inhibitors for Protein Tyrosine Kinases (PTKs) such as Genistein, K252a/b,
Continue readingInvolvement of Ca2+ in the Apoptotic Process – “Friends or Foes”
Over the past two decades, the ubiquitous position of Ca2+ signaling in cellular apoptosis has been carefully investigated. The body …
Continue readingT Cell Signaling and Activation: No Simple Matter
T cells are central players of the adaptive immune response, which help protect the host against different pathogens ranging from …
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