Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of plasma membrane, which then buds off inside the cell to form a vesicle containing the ingested material. Endocytosis includes pinocytosis and phagocytosis. It is a form of active transport.
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular response. Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used. The changes elicited by ligand binding in a receptor give rise to a signaling cascade, which is a chain of biochemical events along a signaling pathway. When signaling pathways interact with one another they form networks, which allow cellular responses to be coordinated, often by combinatorial signaling events. At the molecular level, such responses include changes in the transcription or translation of genes, and post-translational and conformational changes in proteins, as well as changes in their location. These molecular events are the basic mechanisms controlling cell growth, proliferation, metabolism and many other processes. In multicellular organisms, signal transduction pathways have evolved to regulate cell communication in a wide variety of ways.
Membrane proteins are proteins that interact with, or are part of, biological membranes. They include integral membrane proteins that are permanently anchored or part of the membrane and peripheral membrane proteins that are only temporarily attached to the lipid bilayer or to other integral proteins. The integral membrane proteins are classified as transmembrane proteins that span across the membrane and integral monotopic proteins that are attached to only one side of the membrane. Membrane proteins are a common type of proteins along with soluble globular proteins, fibrous proteins, and disordered proteins. They are targets of over 50% of all modern medicinal drugs. It is estimated that 20–30% of all genes in most genomes encode membrane proteins.
The signal recognition particle (SRP) is an abundant, cytosolic, universally conserved ribonucleoprotein that recognizes and targets specific proteins to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes.
Autophagy is the natural, regulated mechanism of the cell that disassembles unnecessary or dysfunctional components. It allows the orderly degradation and recycling of cellular components.
Don Craig Wiley was an American structural biologist.
The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory compound in the mature vertebrate central nervous system. There are two classes of GABA receptors: GABAA and GABAB. GABAA receptors are ligand-gated ion channels ; whereas GABAB receptors are G protein-coupled receptors, also called metabotropic receptors.
Robert Huber is a German biochemist and Nobel laureate. known for his work crystallizing an intramembrane protein important in photosynthesis and subsequently applying X-ray crystallography to elucidate the protein's structure.
Smoothened is a protein that in humans is encoded by the SMO gene. Smoothened is a Class Frizzled G protein-coupled receptor that is a component of the hedgehog signaling pathway and is conserved from flies to humans. It is the molecular target of the natural teratogen cyclopamine. It also is the target of Vismodegib, the first hedgehog pathway inhibitor to be approved by the U.S. Food and Drug Administration (FDA).
The Spitzenkörper is a structure found in fungal hyphae that is the organizing center for hyphal growth and morphogenesis. It consists of many small vesicles and is present in growing hyphal tips, during spore germination and where branch formation occurs. Its position in the hyphal tip correlates with the direction of hyphal growth. The Spitzenkörper is a part of the endomembrane system in fungi.
Leptin receptor also known as LEP-R or OB-R is a Type I cytokine receptor, a protein that in humans is encoded by the LEPR gene. LEP-R functions as a receptor for the fat cell-specific hormone leptin. LEP-R has also been designated as CD295. Its location is the cell membrane, and it has extracellular, trans-membrane, and intracellular sections.
Transitional endoplasmic reticulum ATPase also known as valosin-containing protein (VCP) or p97 in mammals and CDC48 in S. Cerevisiae, is an enzyme that in humans is encoded by the VCP gene. The TER ATPase is an ATPase enzyme present in all eukaryotes and archaebacteria. Its main function is to segregate protein molecules from large cellular structures such as protein assemblies, organelle membranes and chromatin, and thus facilitate the degradation of released polypeptides by the multi-subunit protease proteasome.
Ephrin A1 is a protein that in humans is encoded by the EFNA1 gene.
ATP synthase F1 subunit alpha, mitochondrial is an enzyme that in humans is encoded by the ATP5F1A gene.
Peroxisomal membrane protein PEX14 is a protein that in humans is encoded by the PEX14 gene.
Vesicle-associated membrane protein 3 is a protein that in humans is encoded by the VAMP3 gene.
Cell surface receptors are receptors that are embedded in the plasma membrane of cells. They act in cell signaling by receiving extracellular molecules. They are specialized integral membrane proteins that allow communication between the cell and the extracellular space. The extracellular molecules may be hormones, neurotransmitters, cytokines, growth factors, cell adhesion molecules, or nutrients; they react with the receptor to induce changes in the metabolism and activity of a cell. In the process of signal transduction, ligand binding affects a cascading chemical change through the cell membrane.
Gabriel Waksman FMedSci, FRS, is Courtauld professor of biochemistry and molecular biology at University College London (UCL), and professor of structural and molecular biology at Birkbeck College, University of London. He is the director of the Institute of Structural and Molecular Biology (ISMB) at UCL and Birkbeck, head of the Department of Structural and Molecular Biology at UCL, and head of the Department of Biological Sciences at Birkbeck.
Peter Malcolm Colman is the head of the structural biology division at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia.
The Calcium-Dependent Chloride Channel (Ca-ClC) proteins (or calcium-activated chloride channels, are heterogeneous groups of ligand-gated ion channels for chloride that have been identified in many epithelial and endothelial cell types as well as in smooth muscle cells. They include proteins from several structurally different families: chloride channel accessory, bestrophin, and calcium-dependent chloride channel anoctamin channels]] ANO1 is highly expressed in human gastrointestinal interstitial cells of Cajal, which are proteins which serve as intestinal pacemakers for peristalsis. In addition to their role as chloride channels some CLCA proteins function as adhesion molecules and may also have roles as tumour suppressors. These eukaryotic proteins are "required for normal electrolyte and fluid secretion, olfactory perception, and neuronal and smooth muscle excitability" in animals. Members of the Ca-CIC family are generally 600 to 1000 amino acyl residues in length and exhibit 7 to 10 transmembrane segments.
