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Alpha-enolase
Enolase 1 (ENO1), more commonly known as alpha-enolase, is a glycolytic enzyme expressed in most tissues, one of the isozymes of enolase. Each isoenzyme is a homodimer composed of 2 alpha, 2 gamma, or 2 beta subunits, and functions as a glycolytic enzyme. Alpha-enolase, in addition, functions as a structural lens protein (tau-crystallin) in the monomeric form. Alternative splicing of this gene results in a shorter isoform that has been shown to bind to the ''c-myc'' promoter and function as a tumor suppressor. Several pseudogenes have been identified, including one on the long arm of chromosome 1. Alpha-enolase has also been identified as an autoantigen in Hashimoto encephalopathy. Structure ENO1 is one of three enolase isoforms, the other two being ENO2 (ENO-γ) and ENO3 (ENO-β). Each isoform is a protein subunit that can hetero- or homodimerize to form αα, αβ, αγ, ββ, and γγ dimers. The ''ENO1'' gene spans 18 kb and lacks a TATA box while possessing multipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ENO3
Enolase 3 (ENO3), more commonly known as beta-enolase (ENO-β), is an enzyme that in humans is encoded by the ''ENO3'' gene. This gene encodes one of the three enolase isoenzymes found in mammals. This isoenzyme is found in skeletal muscle cells in the adult where it may play a role in muscle development and regeneration. A switch from alpha enolase to beta enolase occurs in muscle tissue during development in rodents. Mutations in this gene have been associated with glycogen storage disease. Alternatively spliced transcript variants encoding different isoforms have been described. rovided by RefSeq, Jul 2010ref name="entrez"> Structure ENO3 is one of three enolase isoforms, the other two being ENO1 (ENO-α) and ENO2 (ENO-γ). Each isoform is a protein subunit that can form hetero- or homodimers of the following combinations: αα, αβ, αγ, ββ, and γγ. Gene The ''ENO3'' gene spans 6 kb and contains 12 exons, though the first exon is an untranslated region and, thus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycolysis
Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH). Glycolysis is a sequence of ten reactions catalyzed by enzymes. Glycolysis is a metabolic pathway that does not require oxygen (In anaerobic conditions pyruvate is converted to lactic acid). The wide occurrence of glycolysis in other species indicates that it is an ancient metabolic pathway. Indeed, the reactions that make up glycolysis and its parallel pathway, the pentose phosphate pathway, occur in the oxygen-free conditions of the Archean oceans, also in the absence of enzymes, catalyzed by metal. In most organisms, glycolysis occurs in the liquid part of cells, the cytosol. The most common type of glycolysis is the ''Embden–Meyerhof–Parnas (EMP) pathway'', which was discovered by Gustav Embden, Otto Meyerhof, and Jakub Karol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Start Codon
The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and Archaea and a N-formylmethionine (fMet) in bacteria, mitochondria and plastids. The most common start codon is AUG (i.e., ATG in the corresponding DNA sequence). The start codon is often preceded by a 5' untranslated region ( 5' UTR). In prokaryotes this includes the ribosome binding site. Alternative start codons Alternative start codons are different from the standard AUG codon and are found in both prokaryotes (bacteria and archaea) and eukaryotes. Alternate start codons are still translated as Met when they are at the start of a protein (even if the codon encodes a different amino acid otherwise). This is because a separate transfer RNA (tRNA) is used for initiation. Eukaryotes Alternate start codons (non-AUG) are very rare in eukaryotic genomes. However, naturally occurring non-AUG start codons have been rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protooncogene
An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels.Kimball's Biology Pages. "Oncogenes" Free full text Most normal cells will undergo a programmed form of rapid cell death () when critical functions are altered and malfunctioning. Activated oncogenes can cause those cells designated for apoptosis to survive and proliferate instead. Most oncogenes began as proto-oncogenes: normal genes involved in cell growth and proliferation or inhibition of apoptosis. If, through mutation, normal genes promoting cellular growth are up-regulated (gain-of-function mutation), they will predisp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long stands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Weight
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentially m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warburg Effect (oncology)
In oncology, the Warburg effect () is the observation that most cancer cells produce energy predominantly not through the 'usual' citric acid cycle and oxidative phosphorylation in the mitochondria as observed in normal cells, but through a less efficient process of 'aerobic glycolysis' consisting of high level of glucose uptake and glycolysis followed by lactic acid fermentation taking place in the cytosol, not the mitochondria, even in the presence of abundant oxygen. This observation was first published by Otto Heinrich Warburg, who was awarded the 1931 Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme". The precise mechanism and therapeutic implications of the Warburg effect, however, remain unclear. In fermentation, the last product of glycolysis, pyruvate, is converted into lactate (lactic acid fermentation) or ethanol (alcoholic fermentation). While fermentation produces adenosine triphosphate (ATP) only in low yield co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promoter (genetics)
In genetics, a promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter. The RNA transcript may encode a protein (mRNA), or can have a function in and of itself, such as tRNA or rRNA. Promoters are located near the transcription start sites of genes, upstream on the DNA (towards the 5' region of the sense strand). Promoters can be about 100–1000 base pairs long, the sequence of which is highly dependent on the gene and product of transcription, type or class of RNA polymerase recruited to the site, and species of organism. Promoters control gene expression in bacteria and eukaryotes. RNA polymerase must attach to DNA near a gene for transcription to occur. Promoter DNA sequences provide an enzyme binding site. The -10 sequence is TATAAT. -35 sequences are conserved on average, but not in most promoters. Artificial promoters with conserved -10 and -35 elements transcribe more slowly. All D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxia (medical)
Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. Hypoxia may be classified as either '' generalized'', affecting the whole body, or ''local'', affecting a region of the body. Although hypoxia is often a pathological condition, variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise.. Hypoxia differs from hypoxemia and anoxemia, in that hypoxia refers to a state in which oxygen present in a tissue or the whole body is insufficient, whereas hypoxemia and anoxemia refer specifically to states that have low or no oxygen in the blood. Hypoxia in which there is complete absence of oxygen supply is referred to as anoxia. Hypoxia can be due to external causes, when the breathing gas is hypoxic, or internal causes, such as reduced effectiveness of gas transfer in the lungs, reduced capacity of the blood to carry oxygen, compromised general ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Start Site
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
