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RAD21
Double-strand-break repair protein rad21 homolog is a protein that in humans is encoded by the ''RAD21'' gene. ''RAD21'' (also known as ''Mcd1'', ''Scc1'', ''KIAA0078'', ''NXP1'', ''HR21''), an essential gene, encodes a DNA double-strand break (DSB) repair protein that is evolutionarily conserved in all eukaryotes from budding yeast to humans. RAD21 protein is a structural component of the highly conserved cohesin complex consisting of RAD21, SMC1A, SMC3, and SCC3 STAG1.html" ;"title="STAG1">STAG1 (SA1) and STAG2 (SA2) in multicellular organisms] proteins, involved in Establishment of sister chromatid cohesion, sister chromatid cohesion. Discovery ''rad21'' was first cloned by Birkenbihl and Subramani in 1992 by complementing the radiation sensitivity of the ''rad21-45'' mutant fission yeast, ''Schizosaccharomyces pombe'', and the murine and human homologs of ''S. pombe'' rad21 were cloned by McKay, Troelstra, van der Spek, Kanaar, Smit, Hagemeijer, Bootsma and Hoeijmake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cohesin
Cohesin is a protein complex that mediates sister chromatid cohesion, homologous recombination, and DNA looping. Cohesin is formed of SMC3, SMC1, SCC1 and SCC3 ( SA1 or SA2 in humans). Cohesin holds sister chromatids together after DNA replication until anaphase when removal of cohesin leads to separation of sister chromatids. The complex forms a ring-like structure and it is believed that sister chromatids are held together by entrapment inside the cohesin ring. Cohesin is a member of the SMC family of protein complexes which includes Condensin, MukBEF and SMC-ScpAB. Cohesin was separately discovered in budding yeast by Douglas Koshland and Kim Nasmyth. Structure Cohesin is a multi-subunit protein complex, made up of SMC1, SMC3, RAD21 and SCC3 (SA1 or SA2). SMC1 and SMC3 are members of the Structural Maintenance of Chromosomes (SMC) family. SMC proteins have two main structural characteristics: an ATP-binding cassette-like 'head' domain with ATPase activity ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMC3
Structural maintenance of chromosomes protein 3 (SMC3) is a protein that in humans is encoded by the SMC3 gene. SMC3 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. Cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2. In humans, SMC3 is present in all cohesin complexes whereas there are multiple paralogs for the other subunits. SMC3 is a member of the SMC protein family. Members of this family are key regulators of DNA repair, chromosome condensation and chromosome segregation. Structure and interactions The domain organisation of SMC proteins is evolutionarily conserved and is composed of an N-terminal Walker A motif, coiled-coil, "hinge", coiled-coil and a C-terminal Walker B motif. The protein folds back on itself to form a rod-shaped molecule with a heterodimerisation "hinge" domain at one end and an ABC-type ATPase "head" at the other. These globular domains are separated by a ~50 n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMC1A
Structural maintenance of chromosomes protein 1A (SMC1A) is a protein that in humans is encoded by the ''SMC1A'' gene. SMC1A is a subunit of the cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells, cohesin is formed of SMC1A, SMC3, RAD21 and either SA1 or SA2 whereas in meiosis, cohesin is formed of SMC3, SMC1B, REC8 and SA3. SMC1A is a member of the SMC protein family. Members of this family are key regulators of DNA repair, chromosome condensation and chromosome segregation from bacteria to humans. Structure The domain organisation of SMC proteins is highly conserved and is composed of an N-terminal Walker A motif, coiled-coil, "hinge", coiled-coil and a C-terminal Walker B motif. The protein folds back on itself to form a rod-shaped molecule with a heterodimerisation "hinge" domain at one end and an ABC-type ATPase "head" at the other. These globular domains are separated by a ~50 nm anti-parallel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STAG1
Cohesin subunit SA-1 (SA1) is a protein that in humans is encoded by the ''STAG1'' gene. SA1 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2 whereas in meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately ..., cohesin is formed of SMC3, SMC1B, REC8 and SA3. Structure and Interactions SA1 is one of three human homologues of the yeast protein Scc3 which is a core subunit of the cohesin complex (the three human paralogues are SA1, SA2 and SA3). SA1 and SA2 are expressed in somatic cells whereas SA3 is the main SA paralogue in meiotic cells. SA1 stably binds to cohesin via the RAD21 subunit and functions as a platform for other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Separase
Separase, also known as separin, is a cysteine protease responsible for triggering anaphase by hydrolysing cohesin, which is the protein responsible for binding sister chromatids during the early stage of anaphase. In humans, separin is encoded by the ''ESPL1'' gene. History In '' S. cerevisiae'', separase is encoded by the ''esp1'' gene. Esp1 was discovered by Kim Nasmyth and coworkers in 1998. In 2021, structures of human separase were determined in complex with either securin or CDK1-cyclin B1-CKS1 using cryo-EM by scientists of the University of Geneva. Function Stable cohesion between sister chromatids before anaphase and their timely separation during anaphase are critical for cell division and chromosome inheritance. In vertebrates, sister chromatid cohesion is released in 2 steps via distinct mechanisms. The first step involves phosphorylation of STAG1 or STAG2 in the cohesin complex. The second step involves cleavage of the cohesin subunit SCC1 (RAD21) by separas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Establishment Of Sister Chromatid Cohesion
Sister chromatid cohesion refers to the process by which sister chromatids are paired and held together during certain phases of the cell cycle. Establishment of sister chromatid cohesion is the process by which chromatin-associated cohesin protein becomes competent to physically bind together the sister chromatids. In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. Some studies have suggested that cohesion aids in aligning the kinetochores during mitosis by forcing the kinetochores to face opposite cell poles. Cohesin loading Cohesin first associates with the chromosomes during G1 phase. The cohesin ring is composed of two SMC (structural maintenance of chromosomes) proteins and two additional Scc proteins. Cohesin may originally interact with chromosomes via the ATPase domains of the SMC proteins. In yeast, the loading of cohesin on the chromosomes depends on proteins Scc2 and Scc4. Cohesi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STAG2
Cohesin subunit SA-2 (SA2) is a protein that in humans is encoded by the ''STAG2'' gene. SA2 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2 whereas in meiosis, cohesin is formed of SMC3, SMC1B, REC8 and SA3. ''STAG2'' is frequently mutated in a range of cancers and several other disorders. Function SA2 is part of the cohesin complex, which is a structure that holds the sister chromatids together after DNA replication. STAG2 has been shown to interact with STAG1 Cohesin subunit SA-1 (SA1) is a protein that in humans is encoded by the ''STAG1'' gene. SA1 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells cohesin is form .... Role in Disease Of the cohesin complex, STAG2 is the subunit where the most variants have been reported in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Chromatids
A sister chromatid refers to the identical copies (chromatids) formed by the DNA replication of a chromosome, with both copies joined together by a common centromere. In other words, a sister chromatid may also be said to be 'one-half' of the duplicated chromosome. A pair of sister chromatids is called a dyad. A full set of sister chromatids is created during the synthesis ( S) phase of interphase, when all the chromosomes in a cell are replicated. The two sister chromatids are separated from each other into two different cells during mitosis or during the second division of meiosis. Compare sister chromatids to homologous chromosomes, which are the two ''different'' copies of a chromosome that diploid organisms (like humans) inherit, one from each parent. Sister chromatids are by and large identical (since they carry the same alleles, also called variants or versions, of genes) because they derive from one original chromosome. An exception is towards the end of meiosis, after c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure 2 Cohesin Complex And Models
Figure may refer to: General *A shape, drawing, depiction, or geometric configuration *Figure (wood), wood appearance *Figure (music), distinguished from musical motif * Noise figure, in telecommunication * Dance figure, an elementary dance pattern *A person's figure, human physical appearance Arts *Figurine, a miniature statuette representation of a creature *Action figure, a posable jointed solid plastic character figurine *Figure painting, realistic representation, especially of the human form *Figure drawing *Model figure, a scale model of a creature Writing *figure, in writing, a type of floating block (text, table, or graphic separate from the main text) *Figure of speech, also called a rhetorical figure * Christ figure, a type of character * in typesetting, text figures and lining figures Accounting *Figure, a synonym for number *Significant figures in a decimal number Science *Figure of the Earth, the size and shape of the Earth in geodesy Sports *Figure (horse), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritance. This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA. The cell possesses the distinctive property of division, which makes replication of DNA essential. DNA is made up of a double helix of two complementary strands. The double helix describes the appearance of a double-stranded DNA which is thus composed of two linear strands that run opposite to each other and twist together to form. During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, a process referred to as semiconservative replication. As a result of semi-conservativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schlegel's Japanese Gecko
Schlegel's Japanese gecko (''Gekko japonicus''), also known as ''yamori'' in Japanese, is a species of gecko. It is found in eastern China, Japan, and South Korea. Distribution ''Gekko japonicus'' occurs across the main islands of Japan, ranging from northern Honshu in the north and east to Kyushu in the south and west. Ecology Like other species of gecko, individuals of ''G. japonicus'' primarily eat insects. The species is capable of autotomy Autotomy (from the Greek ''auto-'', "self-" and ''tome'', "severing", αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usually as a self-defense mechanism to elude ..., and will separate its tail from its body to escape predators. While this process avoids bleeding, as blood vessels at the base of the tail close to prevent blood loss, the gecko does lose a supply of fat tissue, which it can use during periods where food is scarce. Japanese culture In Japa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_and_SMC1_(green)_(PDB_2WD5)_from_mice_(Kurze_et_al._2009).png "Click for more on -> SMC3")
_and_RAD21_(green)_(PDB_4PK7).png "Click for more on -> STAG1")
