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MAP1LC3B
Microtubule-associated proteins 1A/1B light chain 3B (hereafter referred to as LC3) is a protein that in humans is encoded by the ''MAP1LC3B'' gene. LC3 is a central protein in the autophagy pathway where it functions in autophagy substrate selection and autophagosome biogenesis. LC3 is the most widely used marker of autophagosomes. Discovery LC3 was originally identified as a microtubule associated protein in rat brain. However it was later found that the primary function of LC3 is in autophagy, a process that involves the bulk degradation of cytoplasmic components. The ATG8 protein family MAP1LC3B is a member of the highly conserved ATG8 protein family. ATG8 proteins are present in all known eukaryotic organisms. The animal ATG8 family comprises three subfamilies: (i) microtubule-associated protein 1 light chain 3 (MAP1LC3); (ii) Golgi-associated ATPase enhancer of 16 kDa (GATE-16); and (iii) γ-amino-butyric acid receptor-associate protein (GABARAP). ''MAP1LC3B'' is on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAP1LC3B2
Microtubule-associated proteins 1A/1B light chain 3B (hereafter referred to as LC3) is a protein that in humans is encoded by the ''MAP1LC3B'' gene. LC3 is a central protein in the autophagy pathway where it functions in autophagy substrate selection and autophagosome biogenesis. LC3 is the most widely used marker of autophagosomes. Discovery LC3 was originally identified as a microtubule associated protein in rat brain. However it was later found that the primary function of LC3 is in autophagy, a process that involves the bulk degradation of cytoplasmic components. The ATG8 protein family MAP1LC3B is a member of the highly conserved ATG8 protein family. ATG8 proteins are present in all known eukaryotic organisms. The animal ATG8 family comprises three subfamilies: (i) microtubule-associated protein 1 light chain 3 (MAP1LC3); (ii) Golgi-associated ATPase enhancer of 16 kDa (GATE-16); and (iii) γ-amino-butyric acid receptor-associate protein (GABARAP). ''MAP1LC3B'' is on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATG8
Autophagy-related protein 8 (Atg8) is a ubiquitin-like protein required for the formation of autophagosomal membranes. The transient conjugation of Atg8 to the autophagosomal membrane through a ubiquitin-like conjugation system is essential for autophagy in eukaryotes. Even though there are homologues in animals (see for example GABARAP, GABARAPL1, GABARAPL2, MAP1LC3A, MAP1LC3B, MAP1LC3B2, and MAP1LC3C), this article mainly focuses on its role in lower eukaryotes such as ''Saccharomyces cerevisiae''. Structure Atg8 is a monomer of 117 aminoacids and a molecular weight of 13,6kDa. It consists of a 5-stranded β-sheet, which is enclosed by two α-helices at one side and one α-helix at the other side and exhibits a conserved GABARAP domain. Even though Atg8 does not show a clear sequence homology to ubiquitin, its crystal structure reveals a conserved ubiquitin-like fold. Function In autophagy Atg8 is one of the key molecular components involved in autophagy, the cellular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATG5
Autophagy related 5 (ATG5) is a protein that, in humans, is encoded by the ''ATG5'' gene located on Chromosome 6. It is an E3 ubi autophagic cell death. ATG5 is a key protein involved in the extension of the phagophoric membrane in autophagic vesicles. It is activated by ATG7 and forms a complex with ATG12 and ATG16L1. This complex is necessary for LC3-I (microtubule-associated proteins 1A/1B light chain 3B) conjugation to PE (phosphatidylethanolamine) to form LC3-II (LC3-phosphatidylethanolamine conjugate). ATG5 can also act as a pro-apoptotic molecule targeted to the mitochondria. Under low levels of DNA damage, ATG5 can translocate to the nucleus and interact with survivin. ATG5 is known to be regulated via various stress induced transcription factors and protein kinases. Structure ATG5 comprises three domains: a ubiquitin-like N-terminal domain (UblA), a helix-rich domain (HR) and a ubiquitin-like C-terminal domain (UblB). The three domains are connected by two linke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAP1LC3A
Microtubule-associated proteins 1A/1B light chain 3A is a protein that in humans is encoded by the ''MAP1LC3A'' gene. Two transcript variants encoding different isoforms have been found for this gene. Function MAP1A and MAP1B are microtubule-associated proteins which mediate the physical interactions between microtubules and components of the cytoskeleton. MAP1A and MAP1B each consist of a heavy chain subunit and multiple light chain subunits. The protein encoded by this gene is one of the light chain subunits and can associate with either MAP1A or MAP1B. MAPLC3A is one of the mammalian homologues of yeast ATG8, an important marker and effector of autophagy. Regulation MAP1LC3A is regulated by several post-translational modifications. These include covalent linkage of the C-terminus to phosphatidylethanolamine in autophagic membranes, and phosphorylation by protein kinase A, which downregulates its autophagy functions. Noncovalent interactions are important for its car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATG4B
Cysteine protease ATG4B is an enzyme that in humans is encoded by the ''ATG4B'' gene. Function Autophagy is the process by which endogenous proteins and damaged organelles are destroyed intracellularly. Autophagy is postulated to be essential for cell homeostasis and cell remodeling during differentiation, metamorphosis, non-apoptotic cell death, and aging. Reduced levels of autophagy have been described in some malignant tumors, and a role for autophagy in controlling the unregulated cell growth linked to cancer has been proposed. This gene encodes a member of the autophagin protein family. The encoded protein is also designated as a member of the C-54 family of cysteine proteases. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. One main function of Atg4 is to cleave the pre-protein of Atg8, leading to the non-lipidated soluble (-I) form which can be processed further by Atg3, Atg7, Atg5-12 into the lipidated form (-II) anchored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosomal Protein
A ribosomal protein (r-protein or rProtein) is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. ''E. coli'', other bacteria and Archaea have a 30S small subunit and a 50S large subunit, whereas humans and yeasts have a 40S small subunit and a 60S large subunit. Equivalent subunits are frequently numbered differently between bacteria, Archaea, yeasts and humans. A large part of the knowledge about these organic molecules has come from the study of '' E. coli'' ribosomes. All ribosomal proteins have been isolated and many specific antibodies have been produced. These, together with electronic microscopy and the use of certain reactives, have allowed for the determination of the topography of the proteins in the ribosome. More recently, a near-complete (near)atomic picture of the ribosomal proteins is emerging from the latest high-resolution cryo-EM data (including ). Conservation Ribosomal prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulin
Tubulin in molecular biology can refer either to the tubulin protein superfamily of globular proteins, or one of the member proteins of that superfamily. α- and β-tubulins polymerize into microtubules, a major component of the eukaryotic cytoskeleton. Microtubules function in many essential cellular processes, including mitosis. Tubulin-binding drugs kill cancerous cells by inhibiting microtubule dynamics, which are required for DNA segregation and therefore cell division. In eukaryotes, there are six members of the tubulin superfamily, although not all are present in all species.Turk E, Wills AA, Kwon T, Sedzinski J, Wallingford JB, Stearns "Zeta-Tubulin Is a Member of a Conserved Tubulin Module and Is a Component of the Centriolar Basal Foot in Multiciliated Cells"Current Biology (2015) 25:2177-2183. Both α and β tubulins have a mass of around 50 kDa and are thus in a similar range compared to actin (with a mass of ~42 kDa). In contrast, tubulin polymers (microtubules) te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAP1B
Microtubule-associated protein 1B is a protein that in humans is encoded by the ''MAP1B'' gene. Function This gene encodes a protein that belongs to the microtubule-associated protein family. The proteins of this family are thought to be involved in microtubule assembly, which is an essential step in neurogenesis. The product of this gene is a precursor polypeptide that presumably undergoes proteolytic processing to generate the final MAP1B heavy chain and LC1 light chain. Gene knockout studies of the mouse microtubule-associated protein 1B gene suggested an important role in development and function of the nervous system. Two alternatively spliced transcript variants have been described. Interactions MAP1B has been shown to interact with Acidic leucine-rich nuclear phosphoprotein 32 family member A and RASSF1 Ras association domain-containing protein 1 is a protein that in humans is encoded by the ''RASSF1'' gene. Function This gene encodes a protein similar to the RA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleolus
The nucleolus (, plural: nucleoli ) is the largest structure in the nucleus of eukaryotic cells. It is best known as the site of ribosome biogenesis, which is the synthesis of ribosomes. The nucleolus also participates in the formation of signal recognition particles and plays a role in the cell's response to stress. Nucleoli are made of proteins, DNA and RNA, and form around specific chromosomal regions called nucleolar organizing regions. Malfunction of nucleoli can be the cause of several human conditions called "nucleolopathies" and the nucleolus is being investigated as a target for cancer chemotherapy. History The nucleolus was identified by bright-field microscopy during the 1830s. Little was known about the function of the nucleolus until 1964, when a study of nucleoli by John Gurdon and Donald Brown in the African clawed frog ''Xenopus laevis'' generated increasing interest in the function and detailed structure of the nucleolus. They found that 25% of the frog e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Lamina
The nuclear lamina is a dense (~30 to 100 nm thick) fibrillar network inside the nucleus of eukaryote cells. It is composed of intermediate filaments and membrane associated proteins. Besides providing mechanical support, the nuclear lamina regulates important cellular events such as DNA replication and cell division. Additionally, it participates in chromatin organization and it anchors the nuclear pore complexes embedded in the nuclear envelope. The nuclear lamina is associated with the inner face of the inner nuclear membrane of the nuclear envelope, whereas the outer face of the outer nuclear membrane is continuous with the endoplasmic reticulum. The nuclear lamina is similar in structure to the nuclear matrix, that extends throughout the nucleoplasm. Structure and composition The nuclear lamina consists of two components, lamins and nuclear lamin-associated membrane proteins. The lamins are type V intermediate filaments which can be categorized as either A-type (lam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamin B1
Lamin-B1 is a protein that in humans is encoded by the ''LMNB1'' gene. The nuclear lamina consists of a two-dimensional matrix of proteins located next to the inner nuclear membrane. The lamin family of proteins make up the matrix and are highly conserved in evolution. During mitosis, the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated. Lamin proteins are thought to be involved in nuclear stability, chromatin structure, and gene expression. Vertebrate lamins consist of two types, A and B. This gene encodes one of the two B type proteins, B1. Lamin B, along with heterochromatin, is anchored to the inner surface of the nuclear membrane by the lamin B receptor. Interactions LMNB1 has been shown to interact with Thymopoietin. Pathology Mutations affecting the LMNB1 gene cause autosomal dominant adult-onset demyelinating leukodystrophy. See also * Lamin B2 Lamin B2 is a protein that in humans is encoded by the ''LMNB2'' gene. It is the second o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
