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Phosphatidylinositol 3-phosphate-binding Protein 2
Phosphatidylinositol 3-phosphate-binding protein 2 (Pib2) is a yeast protein involved in the regulation of TORC1 signaling and lysosomal membrane permeabilization. It is essential for the reactivation of TORC1 following exposure to rapamycin or nutrient starvation. Discovery Pib2 was first identified as a FYVE domain-containing protein able to bind phosphatidylinositol 3-phosphate (PI3P). Pib2 was later identified in a screen for rapamycin sensitivity, along with several other TORC1 regulatory proteins (including Ego1, Gtr1, Gtr2, and other key TORC1 related proteins). Structure Pib2 is a 70.6 kDa protein with 635 amino acids (Uniprot - P53191). Pib2 has 5 weakly conserved motifs among fungi and 2 universally conserved motifs. The partially conserved motifs are found in the N-terminal region of the protein and are generally referred to as regions A-E The universally conserved motifs include a phosphatidylinositol-3-phosphate (PI3P)-binding FYVE domain, and a short tail mot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharomyces Cerevisiae
''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been originally isolated from the skin of grapes. It is one of the most intensively studied eukaryotic model organisms in molecular biology, molecular and cell biology, much like ''Escherichia coli'' as the model bacteria, bacterium. It is the microorganism behind the most common type of fermentation (biochemistry), fermentation. ''S. cerevisiae'' cells are round to ovoid, 5–10 micrometre, μm in diameter. It reproduces by budding. Many proteins important in human biology were first discovered by studying their Homology (biology), homologs in yeast; these proteins include cell cycle proteins, signaling proteins, and protein-processing enzymes. ''S. cerevisiae'' is currently the only yeast cell known to have Berkeley body, Berkeley bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MTORC1
mTORC1, also known as mammalian target of rapamycin complex 1 or mechanistic target of rapamycin complex 1, is a protein complex that functions as a nutrient/energy/redox sensor and controls protein synthesis. mTOR Complex 1 (mTORC1) is composed of the mammalian target of rapamycin, mTOR protein complex, RPTOR, regulatory-associated protein of mTOR (commonly known as raptor), mammalian lethal with SEC13 protein 8 (MLST8), AKT1S1, PRAS40 and DEPTOR. This complex embodies the classic functions of mTOR, namely as a nutrient/energy/redox sensor and controller of protein synthesis. The activity of this complex is regulated by rapamycin, insulin, growth factors, phosphatidic acid, certain amino acids and their derivatives (e.g., leucine, -leucine and β-hydroxy β-methylbutyric acid), mechanical stimuli, and oxidative stress. Recently it has been also demonstrated that cellular bicarbonate metabolism can be regulated by mTORC1 signaling. The role of mTORC1 is to activate translation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapamycin
Sirolimus, also known as rapamycin and sold under the brand name Rapamune among others, is a macrolide compound that is used to coat coronary stents, prevent organ transplant rejection, treat a rare lung disease called lymphangioleiomyomatosis, and treat perivascular epithelioid cell tumor (PEComa). It has immunosuppressant functions in humans and is especially useful in preventing the rejection of kidney transplants. It is a mechanistic target of rapamycin kinase (mTOR) inhibitor that inhibits activation of T cells and B cells by reducing their sensitivity to interleukin-2 (IL-2). It is produced by the bacterium '' Streptomyces hygroscopicus'' and was isolated for the first time in 1972, from samples of ''Streptomyces hygroscopicus'' found on Easter Island. The compound was originally named rapamycin after the native name of the island, Rapa Nui. Sirolimus was initially developed as an antifungal agent. However, this use was abandoned when it was discovered to have potent immu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FYVE Domain
In molecular biology the FYVE zinc finger domain is named after the four cysteine-rich proteins: Fab 1 (yeast orthologue of PIKfyve), YOTB, Vac 1 (vesicle transport protein), and EEA1, in which it has been found. FYVE domains bind phosphatidylinositol 3-phosphate, in a way dependent on its metal ion coordination and basic amino acids. The FYVE domain inserts into cell membranes in a pH-dependent manner. The FYVE domain has been connected to vacuolar protein sorting and endosome function. Structure The FYVE domain is composed of two small beta hairpins (or zinc knuckles) followed by an alpha helix. The FYVE finger binds two zinc ions. The FYVE finger has eight potential zinc coordinating cysteine positions and is characterized by having basic amino acids around the cysteines. Many members of this family also include two histidines in a sequence motif: The FYVE finger is structurally similar to the RING domain and the PHD finger. Examples The following is a list of human prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatidylinositol 3-phosphate
Phosphatidylinositol 3-phosphate (PtdIns3''P'') is a phospholipid found in cell membranes that helps to recruit a range of proteins, many of which are involved in protein trafficking, to the membranes. It is the product of both the class II and III phosphoinositide 3-kinases (PI 3-kinases) activity on phosphatidylinositol. PtdIns3''P'' is dephosphorylated by the myotubularin family of phosphatases, on the D3 position of the inositol ring, and can be converted to PtdIns(3,5)''P''2 by the lipid kinase PIKfyve. Both FYVE domains and PX domains – found in proteins such as SNX1, HGS, and EEA1 – bind to PtdIns3''P''. The majority of PtdIns3''P'' appears to be constitutively synthesised by the class III PI 3-kinase, PIK3C3 (Vps34), at endocytic membranes. Class II PI 3-kinases also appear to synthesise PtdIns3''P'', their activity however appears to be regulated by a range of stimuli, including growth factors. This suggests that specific pools of PtdIns3''P'' may be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''true f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-terminus
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amine group is bonded to the carboxylic group of another amino acid, making it a chain. That leaves a free carboxylic group at one end of the peptide, called the C-terminus, and a free amine group on the other end called the N-terminus. By convention, peptide sequences are written N-terminus to C-terminus, left to right (in LTR writing systems). This correlates the translation direction to the text direction, because when a protein is translated from messenger RNA, it is created from the N-terminus to the C-terminus, as amino acids are added to the carboxyl end of the protein. Chemistry Each amino acid has an amine group and a carboxylic group. Amino acids link to one another by peptide bonds which form through a dehydration reaction that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatidylinositol 3-phosphate
Phosphatidylinositol 3-phosphate (PtdIns3''P'') is a phospholipid found in cell membranes that helps to recruit a range of proteins, many of which are involved in protein trafficking, to the membranes. It is the product of both the class II and III phosphoinositide 3-kinases (PI 3-kinases) activity on phosphatidylinositol. PtdIns3''P'' is dephosphorylated by the myotubularin family of phosphatases, on the D3 position of the inositol ring, and can be converted to PtdIns(3,5)''P''2 by the lipid kinase PIKfyve. Both FYVE domains and PX domains – found in proteins such as SNX1, HGS, and EEA1 – bind to PtdIns3''P''. The majority of PtdIns3''P'' appears to be constitutively synthesised by the class III PI 3-kinase, PIK3C3 (Vps34), at endocytic membranes. Class II PI 3-kinases also appear to synthesise PtdIns3''P'', their activity however appears to be regulated by a range of stimuli, including growth factors. This suggests that specific pools of PtdIns3''P'' may be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus. Chemistry Each amino acid has a carboxyl group and an amine group. Amino acids link to one another to form a chain by a dehydration reaction which joins the amine group of one amino acid to the carboxyl group of the next. Thus polypeptide chains have an end with an unbound carboxyl group, the C-terminus, and an end with an unbound amine group, the N-terminus. Proteins are naturally synthesized starting from the N-terminus and ending at the C-terminus. Function C-terminal retention signals While the N-terminus of a protein often c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleckstrin Homology Domain
Pleckstrin homology domain (PH domain) or (PHIP) is a protein domain of approximately 120 amino acids that occurs in a wide range of proteins involved in intracellular signaling or as constituents of the cytoskeleton. This domain can bind phosphatidylinositol lipids within biological membranes (such as phosphatidylinositol (3,4,5)-trisphosphate and phosphatidylinositol (4,5)-bisphosphate), and proteins such as the βγ-subunits of heterotrimeric G proteins, and protein kinase C. Through these interactions, PH domains play a role in recruiting proteins to different membranes, thus targeting them to appropriate cellular compartments or enabling them to interact with other components of the signal transduction pathways. Lipid binding specificity Individual PH domains possess specificities for phosphoinositides phosphorylated at different sites within the inositol ring, e.g., some bind phosphatidylinositol (4,5)-bisphosphate but not phosphatidylinositol (3,4,5)-trisphosphate or p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuole
A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape or size; its structure varies according to the requirements of the cell. Discovery Contractile vacuoles ("stars") were first observed by Spallanzani (1776) in protozoa, although mistaken for respiratory organs. Dujardin (1841) named these "stars" as ''vacuoles''. In 1842, Schleiden applied the term for plant cells, to distinguish the structure with cell sap from the rest of the protoplasm. In 1885, de Vries named the vacuole membrane as tonoplast. Function The function and signifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosome
Endosomes are a collection of intracellular sorting organelles in eukaryotic cells. They are parts of endocytic membrane transport pathway originating from the trans Golgi network. Molecules or ligands internalized from the plasma membrane can follow this pathway all the way to lysosomes for degradation or can be recycled back to the cell membrane in the endocytic cycle. Molecules are also transported to endosomes from the trans Golgi network and either continue to lysosomes or recycle back to the Golgi apparatus. Endosomes can be classified as early, sorting, or late depending on their stage post internalization. Endosomes represent a major sorting compartment of the endomembrane system in cells. Function Endosomes provide an environment for material to be sorted before it reaches the degradative lysosome. For example, low-density lipoprotein (LDL) is taken into the cell by binding to the LDL receptor at the cell surface. Upon reaching early endosomes, the LDL dissociates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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