DynactinDynactin is a 23 subunit protein complex that acts as a co-factor for the microtubule motor cytoplasmic dynein-1. It is built around a short filament of actin related protein-1 (Arp1). Dynactin was identified as an activity that allowed purified cytoplasmic dynein to move membrane vesicles along microtubules in vitro. It was shown to be a multiprotein complex and named "dynactin" because of its role in dynein activation. The main features of dynactin were visualized by quick-freeze, deep-etch, rotary shadow electron microscopy.
Caenorhabditis elegansCaenorhabditis elegans (ˌsiːnoʊræbˈdaɪtəs_ˈɛləɡæns) is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek caeno- (recent), rhabditis (rod-like) and Latin elegans (elegant). In 1900, Maupas initially named it Rhabditides elegans. Osche placed it in the subgenus Caenorhabditis in 1952, and in 1955, Dougherty raised Caenorhabditis to the status of genus. C.
Cyclin ECyclin E is a member of the cyclin family. Cyclin E binds to G1 phase Cdk2, which is required for the transition from G1 to S phase of the cell cycle that determines initiation of DNA duplication. The Cyclin E/CDK2 complex phosphorylates p27Kip1 (an inhibitor of Cyclin D), tagging it for degradation, thus promoting expression of Cyclin A, allowing progression to S phase. Like all cyclin family members, cyclin E forms a complex with cyclin-dependent kinase (CDK2).
Cell divisionCell division is the process by which a parent cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are two distinct types of cell division: a vegetative division (mitosis), producing daughter cells genetically identical to the parent cell, and a cell division that produces haploid gametes for sexual reproduction (meiosis), reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the daughter cells.
Cell cycleThe cell cycle, or cell-division cycle, is the series of events that take place in a cell that causes it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division. In cells with nuclei (eukaryotes, i.e., animal, plant, fungal, and protist cells), the cell cycle is divided into two main stages: interphase and the mitotic (M) phase (including mitosis and cytokinesis).
Aurora kinase AAurora kinase A also known as serine/threonine-protein kinase 6 is an enzyme that in humans is encoded by the AURKA gene. Aurora A is a member of a family of mitotic serine/threonine kinases. It is implicated with important processes during mitosis and meiosis whose proper function is integral for healthy cell proliferation. Aurora A is activated by one or more phosphorylations and its activity peaks during the G2 phase to M phase transition in the cell cycle. The aurora kinases were first identified in 1990 during a cDNA screen of Xenopus eggs.
AnaphaseAnaphase () is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell. Chromosomes also reach their overall maximum condensation in late anaphase, to help chromosome segregation and the re-formation of the nucleus. Anaphase starts when the anaphase promoting complex marks an inhibitory chaperone called securin for destruction by ubiquitylating it.
KinesinA kinesin is a protein belonging to a class of motor proteins found in eukaryotic cells. Kinesins move along microtubule (MT) filaments and are powered by the hydrolysis of adenosine triphosphate (ATP) (thus kinesins are ATPases, a type of enzyme). The active movement of kinesins supports several cellular functions including mitosis, meiosis and transport of cellular cargo, such as in axonal transport, and intraflagellar transport.
CohesinCohesin 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.
Asymmetric cell divisionAn asymmetric cell division produces two daughter cells with different cellular fates. This is in contrast to symmetric cell divisions which give rise to daughter cells of equivalent fates. Notably, stem cells divide asymmetrically to give rise to two distinct daughter cells: one copy of the original stem cell as well as a second daughter programmed to differentiate into a non-stem cell fate. (In times of growth or regeneration, stem cells can also divide symmetrically, to produce two identical copies of the original cell.
