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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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spindle Assembly 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 chro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaphase Promoting Complex
Anaphase-promoting complex (also called the cyclosome or APC/C) is an E3 ubiquitin ligase that marks target cell cycle proteins for degradation by the 26S proteasome. The APC/C is a large complex of 11–13 subunit proteins, including a cullin (Apc2) and RING (Apc11) subunit much like SCF. Other parts of the APC/C have unknown functions but are highly conserved. It was the discovery of the APC/C (and SCF) and their key role in eukaryotic cell-cycle regulation that established the importance of ubiquitin-mediated proteolysis in cell biology. Once perceived as a system exclusively involved in removing damaged protein from the cell, ubiquitination and subsequent protein degradation by the proteasome is now perceived as a universal regulatory mechanism for signal transduction whose importance approaches that of protein phosphorylation. In 2014, the APC/C was mapped in 3D at a resolution of less than a nanometre, which also uncovered its secondary structure. This finding could ... [...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 Estrogen receptor beta (ERβ) also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2) is one of two main types of estrogen receptor—a nuclear receptor which is activated by the sex hormone estrogen. In humans ERβ is encoded by ..., * MAD2L2, * Mad1, and * UBD. References Further reading * * * * * * * * * * * * * * * * * * {{PDB Gallery, geneid=4085 ... [...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] |
CDC27
Cell division cycle protein 27 homolog is a protein that in humans is encoded by the ''CDC27'' gene. Function The protein encoded by this gene shares strong similarity with Saccharomyces cerevisiae protein Cdc27, and the gene product of Schizosaccharomyces pombe nuc 2. This protein is a component of anaphase-promoting complex (APC), which is composed of eight protein subunits and highly conserved in eucaryotic cells. APC catalyzes the formation of cyclin B-ubiquitin conjugate that is responsible for the ubiquitin-mediated proteolysis of B-type cyclins. This protein and 3 other members of the APC complex contain the TPR (tetratricopeptide repeat), a protein domain important for protein-protein interaction. This protein was shown to interact with mitotic checkpoint proteins including Mad2, p55CDC and BUBR1, and thus may be involved in controlling the timing of mitosis. Interactions CDC27 has been shown to interact with: * ANAPC10, * ANAPC11, * ANAPC1, * ANAPC4, * ANAPC5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FBXO5
F-box only protein 5 is a protein that in humans is encoded by the ''FBXO5'' gene. Function This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of the ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbxs class. This protein is similar to xenopus early mitotic inhibitor-1 (Emi1), which is a mitotic regulator that interacts with Cdc20 and inhibits the anaphase promoting complex. Moreover, Emi1 also assembles a CRL1 complex that targets RAD51 for ubiquitin-mediated degradation. Disease Gene and protein express ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HDAC1
Histone deacetylase 1 (HDAC1) is an enzyme that in humans is encoded by the ''HDAC1'' gene. Function Histone acetylation and deacetylation, catalyzed by multisubunit complexes, play a key role in the regulation of eukaryotic gene expression. The protein encoded by this gene belongs to the histone deacetylase/acuc/apha family and is a component of the histone deacetylase complex. It also interacts with retinoblastoma tumor-suppressor protein and this complex is a key element in the control of cell proliferation and differentiation. Together with metastasis-associated protein-2 MTA2, it deacetylates p53 and modulates its effect on cell growth and apoptosis. Model organisms Model organisms have been used in the study of HDAC1 function. A conditional knockout mouse line, called ''Hdac1tm1a(EUCOMM)Wtsi'' was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclin A1
Cyclin-A1 is a protein that in humans is encoded by the ''CCNA1'' gene. Function The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell division cycle. Cyclins function as activating subunits of enzymatic complex together with cyclin-dependent kinases (CDKs). Different cyclins exhibit distinct expression and degradation patterns that contribute to the temporal coordination of cell cycle events. Cyclin A1 was shown to be expressed in testis and brain, as well as in several leukemic cell lines, and is thought to primarily function in the control of meiosis. This cyclin binds both Cdk1 and Cdk2 kinases, which give two distinct kinase activities, one appearing in S phase, the other in G2, and thus regulate separate functions in cell cycle. This cyclin was found to bind to important cell cycle regulators, such as Rb family proteins, transcription factor E2F1, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDC16
Cell division cycle protein 16 homolog is a protein that in humans is encoded by the ''CDC16'' gene. Function This gene encodes a component protein of the APC complex, which is composed of eight proteins and functions as a protein ubiquitin ligase. The APC complex is a cyclin degradation system that governs exit from mitosis. Each component protein of the APC complex is highly conserved among eukaryotic organisms. This protein and two other APC complex proteins, CDC23 and CDC27, contain a tetratricopeptide repeat (TPR), a protein domain that may be involved in protein-protein interaction. Multiple alternatively spliced variants, encoding the same protein, have been identified. Interactions CDC16 has been shown to interact with CDC27 and 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ANAPC7
Anaphase-promoting complex subunit 7 is an enzyme that in humans is encoded by the ''ANAPC7'' gene. Multiple transcript variants encoding different isoforms have been found for this gene. Function This gene encodes a tetratricopeptide repeat containing component of the anaphase-promoting complex/cyclosome (APC/C), a large E3 ubiquitin ligase that controls cell cycle progression by targeting a number of cell cycle regulators such as B-type cyclins for 26S proteasome-mediated degradation through ubiquitination. The encoded protein is required for proper protein ubiquitination function of APC/C and for the interaction of APC/C with certain transcription coactivators. Interactions ANAPC7 has been shown to interact with ANAPC1, ANAPC4, CDC27 and 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 promo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histone Deacetylase 2
Histone deacetylase 2 (HDAC2) is an enzyme that in humans is encoded by the ''HDAC2'' gene. It belongs to the histone deacetylase class of enzymes responsible for the removal of acetyl groups from lysine residues at the N-terminal region of the core histones (H2A, H2B, H3, and H4). As such, it plays an important role in gene expression by facilitating the formation of transcription repressor complexes and for this reason is often considered an important target for cancer therapy. Though the functional role of the class to which HDAC2 belongs has been carefully studied, the mechanism by which HDAC2 interacts with histone deacetylases of other classes has yet to be elucidated. HDAC2 is broadly regulated by protein kinase 2 (CK2) and protein phosphatase 1 (PP1), but biochemical analysis suggests its regulation is more complex (evinced by the coexistence of HDAC1 and HDAC2 in three distinct protein complexes). Essentially, the mechanism by which HDAC2 is regulated is still unclear by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WD40 Repeat
The WD40 repeat (also known as the WD or beta-transducin repeat) is a short structural motif of approximately 40 amino acids, often terminating in a tryptophan-aspartic acid (W-D) dipeptide. Tandem copies of these repeats typically fold together to form a type of circular solenoid protein domain called the WD40 domain. Structure WD40 domain-containing proteins have 4 to 16 repeating units, all of which are thought to form a circularised beta-propeller structure (see figure to the right). The WD40 domain is composed of several repeats, a variable region of around 20 residues at the beginning followed by a more common repeated set of residues. These repeats typically form a four stranded anti-parallel beta sheet or blade. These blades come together to form a propeller with the most common being a 7 bladed beta propeller. The blades interlock so that the last beta strand of one repeat forms with the first three of the next repeat to form the 3D blade structure. Function WD40-re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
