In chemistry and biology, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (O2), water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (O2H), superoxide (O2-), hydroxyl radical (OH.), and singlet oxygen. ROS are pervasive because they are readily produced from O2, which is abundant. ROS are important in many ways, both beneficial and otherwise. ROS function as signals, that turn on and off biological functions. They are intermediates in the redox behavior of O2, which is central to fuel cells. ROS are central to the photodegradation of organic pollutants in the atmosphere. Most often however, ROS are discussed in a biological context, ranging from their effects on aging and their role in causing dangerous genetic mutations.
Chromatin remodeling is the dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression. Such remodeling is principally carried out by 1) covalent histone modifications by specific enzymes, e.g., histone acetyltransferases (HATs), deacetylases, methyltransferases, and kinases, and 2) ATP-dependent chromatin remodeling complexes which either move, eject or restructure nucleosomes. Besides actively regulating gene expression, dynamic remodeling of chromatin imparts an epigenetic regulatory role in several key biological processes, egg cells DNA replication and repair; apoptosis; chromosome segregation as well as development and pluripotency. Aberrations in chromatin remodeling proteins are found to be associated with human diseases, including cancer. Targeting chromatin remodeling pathways is currently evolving as a major therapeutic strategy in the treatment of several cancers.
FACT complex subunit SSRP1 also known as structure specific recognition protein 1 is a protein that in humans is encoded by the SSRP1 gene.
Transcriptional adapter 3-like is a protein that in humans is encoded by the TADA3 gene. Cytogenetic location: 3p25.3
Transcription initiation protein SPT3 homolog is a protein that in humans is encoded by the SUPT3H gene.
Tardigrades, known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them Kleiner Wasserbär. In 1777, the Italian biologist Lazzaro Spallanzani named them Tardigrada, which means "slow steppers".
Hypsibius dujardini sensu lato is a species complex of tardigrade in the class Eutardigrada. A member of this complex, Hypsibius exemplaris, is widely used for various research projects pertaining to evolutionary biology and astrobiology.
Hypsibius is a genus of tardigrades in the class Eutardigrada.
Diphascon is a genus of water bear or moss piglet, a tardigrade in the class Eutardigrada.
Isohypsibius is a genus of water bear or moss piglet, a tardigrade in the class Eutardigrada. The length of an isohypsibius tardigrade ranges from 0.1 millimeters to 1.5 millimeters. In addition to eating algae and plant cells, tardigrades also consume insect larvae and even other tardigrades. They live in a lot of places, like damp wooded areas with moss, lichens, leaf litter, and dirt. These animals can also be found in natural lakes and ponds.
Acutuncus is a genus of tardigrades containing a single species, Acutuncus antarcticus. Tardigrades, which are eight-legged micro-animals, are commonly referred to as water bears or moss piglets and are found all over the world in varying extreme habitats. First discovered in 1904 and originally named Hypsibius antarcticus, Acutuncus antarcticus is the most abundant tardigrade species in Antarctica.
The retinoblastoma protein is a tumor suppressor protein that is dysfunctional in several major cancers. One function of pRb is to prevent excessive cell growth by inhibiting cell cycle progression until a cell is ready to divide. When the cell is ready to divide, pRb is phosphorylated, inactivating it, and the cell cycle is allowed to progress. It is also a recruiter of several chromatin remodeling enzymes such as methylases and acetylases.
Milnesium is a genus of tardigrades. It is rather common, being found in a wide variety of habitats across the world. It has a fossil record extending back to the Cretaceous, the oldest species found so far is known from Turonian stage deposits on the east coast of the United States. Milnesiums are one of the most desiccation and radiation-resistant invertebrates on Earth because of their unique ability to transform into a "tun" state and utilize intrinsically disordered proteins when experiencing extreme environments.
Echiniscus is a genus of tardigrades in the family Echiniscidae. The genus was named and described by Karl August Sigismund Schultze in 1840.
Pseudechiniscus is a genus of tardigrades in the family Echiniscidae. The genus was named and described by Gustav Thulin in 1911.
Dsup is a DNA-associating protein, unique to the tardigrade, that suppresses the occurrence of DNA breaks by radiation. When human HEK293 cells were engineered with Dsup proteins, they showed approximately 40% more tolerance against X-ray radiation.
Macrobiotidae is a family of tardigrade. As of 2023, it consists of the following genera:
Macrobiotus is a genus of tardigrade consisting of about 100 species.
Bertolanius is a genus of tardigrades belonging to the family Eohypsibiidae.
Mesobiotus is a genus of tardigrades belonging to the family Macrobiotidae.
