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MAD2
Mad2 (mitotic arrest deficient 2) is an essential spindle checkpoint protein. The spindle checkpoint system is a regulatory system that restrains progression through the metaphase-to-anaphase transition. The Mad2 gene was first identified in the yeast ''S. cerevisiae'' in a screen for genes which when mutated would confer sensitivity to microtubule poisons. The human orthologues of Mad2 (MAD2L1 and MAD2L2) were first cloned in a search for human cDNAs that would rescue the microtubule poison-sensitivity of a yeast strain in which a kinetochore binding protein was missing. The protein was shown to be present at unattached kinetochores and antibody inhibition studies demonstrated it was essential to execute a block in the metaphase-to-anaphase transition in response to the microtubule poison nocodazole. Subsequent cloning of the ''Xenopus laevis'' orthologue, facilitated by the sharing of the human sequence, allowed for the characterization of the mitotic checkpoint in egg extracts. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAD2L1
Mitotic spindle assembly checkpoint protein MAD2A is a protein that in humans is encoded by the ''MAD2L1'' gene. Function MAD2L1 is a component of the mitotic spindle assembly checkpoint that prevents the onset of anaphase until all chromosomes are properly aligned at the metaphase plate. MAD2L1 is related to the MAD2L2 gene located on chromosome 1. A MAD2 pseudogene has been mapped to chromosome 14. Interactions MAD2L1 has been shown to interact with: * ADAM17, * BUB1B, * CDC20, * CDC27 and * Estrogen receptor beta, * MAD2L2, * Mad1 Mad1 is a non-essential protein which in yeast has a function in the spindle assembly checkpoint (SAC). This checkpoint monitors chromosome attachment to spindle microtubules and prevents cells from starting anaphase until the spindle is built up ..., and * UBD. References Further reading * * * * * * * * * * * * * * * * * * {{PDB Gallery, geneid=4085 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spindle Checkpoint
The spindle checkpoint, also known as the metaphase-to-anaphase transition, the spindle assembly checkpoint (SAC), the metaphase checkpoint, or the mitotic checkpoint, is a cell cycle checkpoint during mitosis or meiosis that prevents the separation of the duplicated chromosomes (anaphase) until each chromosome is properly attached to the spindle. To achieve proper segregation, the two kinetochores on the sister chromatids must be attached to opposite spindle poles (bipolar orientation). Only this pattern of attachment will ensure that each daughter cell receives one copy of the chromosome. The defining biochemical feature of this checkpoint is the stimulation of the anaphase-promoting complex by M-phase cyclin-CDK complexes, which in turn causes the proteolytic destruction of cyclins and proteins that hold the sister chromatids together. Overview and importance The beginning of metaphase is characterized by the connection of the microtubules to the kinetochores of the chrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAD2L2
Mitotic spindle assembly checkpoint protein MAD2B is a protein that in humans is encoded by the ''MAD2L2'' gene. Function MAD2L2 is a component of the mitotic spindle assembly checkpoint that prevents the onset of anaphase until all chromosomes are properly aligned at the metaphase plate. MAD2L2 is a homolog of MAD2L1. Interactions MAD2L2 has been shown to interact with: * ADAM9, * MAD2L1, * REV1, and * REV3L Protein reversionless 3-like (REV3L) also known as DNA polymerase zeta catalytic subunit (POLZ) is an enzyme that in humans is encoded by the ''REV3L'' gene. The Rev3 subunit interacts with Rev7 to form Pol ζ, a B family polymerase. Pol ζ lacks .... References Further reading * * * * * * * * * * * * * * {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDC20
The cell division cycle protein 20 homolog is an essential regulator of cell division that is encoded by the ''CDC20'' gene in humans. To the best of current knowledge its most important function is to activate the anaphase promoting complex (APC/C), a large 11-13 subunit complex that initiates chromatid separation and entrance into anaphase. The APC/CCdc20 protein complex has two main downstream targets. Firstly, it targets securin for destruction, enabling the eventual destruction of cohesin and thus sister chromatid separation. It also targets S and M-phase (S/M) cyclins for destruction, which inactivates S/M cyclin-dependent kinases (Cdks) and allows the cell to exit from mitosis. A closely related protein, Cdc20homologue-1 (Cdh1) plays a complementary role in the cell cycle. CDC20 appears to act as a regulatory protein interacting with many other proteins at multiple points in the cell cycle. It is required for two microtubule-dependent processes: nuclear movement prior to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BUB3
Mitotic checkpoint protein BUB3 is a protein that in humans is encoded by the ''BUB3'' gene. Bub3 is a protein involved with the regulation of the Spindle checkpoint, Spindle Assembly Checkpoint (SAC); though BUB3 is non-essential in yeast, it is essential in higher eukaryotes. As one of the checkpoint proteins, Bub3 delays the irreversible onset of anaphase through direction of kinetochore localization during prometaphase to achieve biorientation. In directing the kinetochore-microtubule interaction, this ensures the proper (and consequently, bioriented) attachment of the chromosomes prior to anaphase. Bub3 and its related proteins that form the Spindle Assembly Checkpoint (SAC) inhibit the action of the Anaphase-promoting complex, Anaphase Promoting Complex (APC), preventing early anaphase entry and mitotic exit; this serves as a mechanism for the fidelity of chromosomal segregation. Function Bub3 is a crucial component in the formation of the mitotic spindle assembly complex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mad1
Mad1 is a non-essential protein which in yeast has a function in the spindle assembly checkpoint (SAC). This checkpoint monitors chromosome attachment to spindle microtubules and prevents cells from starting anaphase until the spindle is built up. The name Mad refers to the observation that mutant cells are mitotic arrest deficient (MAD) during microtubule depolymerization. Mad1 recruits the anaphase inhibitor Mad2 to unattached kinetochores and is essential for Mad2-Cdc20 complex formation ''in vivo'' but not ''in vitro''. ''In vivo'', Mad1 acts as a competitive inhibitor of the Mad2-Cdc20 complex. Mad1 is phosphorylated by Mps1 which then leads together with other activities to the formation of the mitotic checkpoint complex (MCC). Thereby it inhibits the activity of the anaphase-promoting complex/cyclosome (APC/C). Homologues of Mad1 are conserved in eukaryotes from yeast to mammals. Introduction In the early 90s, yeast genes were identified which mutations resulted in a de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BUB1B
Mitotic checkpoint serine/threonine-protein kinase BUB1 beta is an enzyme that in humans is encoded by the ''BUB1B'' gene. Also known as BubR1, this protein is recognized for its mitotic roles in the spindle assembly checkpoint (SAC) and kinetochore-microtubule interactions that facilitate chromosome migration and alignment. BubR1 promotes mitotic fidelity and protects against aneuploidy by ensuring proper chromosome segregation between daughter cells. BubR1 is proposed to prevent tumorigenesis. Function This gene encodes a kinase involved in spindle checkpoint function and chromosome segregation. The protein has been localized to the kinetochore and plays a role in the inhibition of the anaphase-promoting complex/ cyclosome (APC/C), delaying the onset of anaphase and ensuring proper chromosome segregation. Impaired spindle checkpoint function has been found in many forms of cancer. Increased expression of BubR1 in mice extends a healthy lifespan. * Clinical Significance Bub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetochore
A kinetochore (, ) is a disc-shaped protein structure associated with duplicated chromatids in eukaryotic cells where the spindle fibers attach during cell division to pull sister chromatids apart. The kinetochore assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis and meiosis. The term kinetochore was first used in a footnote in a 1934 Cytology book by Lester W. Sharp and commonly accepted in 1936. Sharp's footnote reads: "The convenient term ''kinetochore'' (= movement place) has been suggested to the author by J. A. Moore", likely referring to John Alexander Moore who had joined Columbia University as a freshman in 1932. Monocentric organisms, including vertebrates, fungi, and most plants, have a single centromeric region on each chromosome which assembles a single, localized kinetochore. Holocentric organisms, such as nematodes and some plants, assemble a kinetochore along the entire length of a chromosome. Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BUB1
Mitotic checkpoint serine/threonine-protein kinase BUB1 also known as BUB1 (budding uninhibited by benzimidazoles 1) is an enzyme that in humans is encoded by the ''BUB1'' gene. Bub1 is a serine/threonine protein kinase first identified in genetic screens of ''Saccharomyces cerevisiae''. The protein is bound to kinetochores and plays a key role in the establishment of the mitotic spindle checkpoint and chromosome congression. The mitotic checkpoint kinase is evolutionarily conserved in organisms as diverse as ''Saccharomyces cerevisiae'' and humans. Loss-of-function mutations or absence of Bub1 has been reported to result in aneuploidy, chromosomal instability ( CIN) and premature senescence. Structure Bub1p comprises a conserved N-terminal region, a central non-conserved region and a C-terminal serine/threonine kinase domain. The N-terminal region mediates binding of Hs-BUB1 to the mitotic kinetochore protein blinkin (a protein also commonly referred to as AF15q14). The latte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, organell ... [...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] |
Mad2exchange
Mad, mad, or MAD may refer to: Geography * Mad (village), a village in the Dunajská Streda District of Slovakia * Mád, a village in Hungary * Adolfo Suárez Madrid–Barajas Airport, by IATA airport code * Mad River (other), several rivers Music Bands * Mad (band), a rock band from Buenos Aires, Argentina * M.A.D (band), a British boyband * M.A.D. (punk band), a 1980s band, which later became Blast * Meg and Dia, an American indie rock band Albums * ''Mad'' (Raven EP), released in 1986 * ''Mad'' (Hadouken! EP), released in 2009 * ''Mad'' (GOT7 EP), released 2015 Songs * "Mad" (Ne-Yo song), 2008 * "Mad", by Dave Dudley from ''Talk of the Town'', 1964 * "Mad", from ''Secret Life of Harpers Bizarre'', 1968 * "Mad", by The Lemonheads from ''Lick'', 1989 * "Mad", from the album ''Magnetic Man'', 2010 * "Mad", by Cassie Steele, 2014 * "M・A・D" (Buck-Tick song), 1991 Organizations * MAD Studio, an architectural firm * Make A Difference, an Indian NGO * Might and De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
