Janus kinaseJanus kinase (JAK) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine-mediated signals via the JAK-STAT pathway. They were initially named "just another kinase" 1 and 2 (since they were just two of many discoveries in a PCR-based screen of kinases), but were ultimately published as "Janus kinase". The name is taken from the two-faced Roman god of beginnings, endings and duality, Janus, because the JAKs possess two near-identical phosphate-transferring domains.
Parkinson's diseaseParkinson's disease (PD), or simply Parkinson's, is a chronic degenerative disorder of the central nervous system that affects both the motor system and non-motor systems. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms become more common. Early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking. Problems may also arise with cognition, behaviour, sleep, and sensory systems. Parkinson's disease dementia becomes common in advanced stages of the disease.
Receptor tyrosine kinaseReceptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins. Receptor tyrosine kinases have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer.
Protein kinase AIn cell biology, protein kinase A (PKA) is a family of serine-threonine kinase whose activity is dependent on cellular levels of cyclic AMP (cAMP). PKA is also known as cAMP-dependent protein kinase (). PKA has several functions in the cell, including regulation of glycogen, sugar, and lipid metabolism. It should not be confused with 5'-AMP-activated protein kinase (AMP-activated protein kinase). Protein kinase A, more precisely known as adenosine 3',5'-monophosphate (cyclic AMP)-dependent protein kinase, abbreviated to PKA, was discovered by chemists Edmond H.
Tyrosine kinaseA tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger class of enzymes known as protein kinases which also attach phosphates to other amino acids such as serine and threonine. Phosphorylation of proteins by kinases is an important mechanism for communicating signals within a cell (signal transduction) and regulating cellular activity, such as cell division.
Lewy bodyLewy bodies are the inclusion bodies – abnormal aggregations of protein – that develop inside nerve cells affected by Parkinson's disease (PD), the Lewy body dementias (Parkinson's disease dementia and dementia with Lewy bodies (DLB)), and some other disorders. They are also seen in cases of multiple system atrophy, particularly the parkinsonian variant (MSA-P). Lewy bodies appear as spherical masses in the cytoplasm that displace other cell components. For instance, some Lewy bodies tend to displace the nucleus to one side of the cell.
Synaptic plasticityIn neuroscience, synaptic plasticity is the ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity. Since memories are postulated to be represented by vastly interconnected neural circuits in the brain, synaptic plasticity is one of the important neurochemical foundations of learning and memory (see Hebbian theory). Plastic change often results from the alteration of the number of neurotransmitter receptors located on a synapse.
Dementia with Lewy bodiesDementia with Lewy bodies (DLB) is a type of dementia characterized by changes in sleep, behavior, cognition, movement, and regulation of automatic bodily functions. Memory loss is not always an early symptom. The disease worsens over time and is usually diagnosed when cognitive impairment interferes with normal daily functioning. Together with Parkinson's disease dementia, DLB is one of the two Lewy body dementias. It is a common form of dementia, but the prevalence is not known accurately and many diagnoses are missed.
KinaseIn biochemistry, a kinase (ˈkaɪneɪs,ˈkɪneɪs,-eɪz) is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group (producing a dephosphorylated substrate and the high energy molecule of ATP).
Protein kinaseA protein kinase is a kinase which selectively modifies other proteins by covalently adding phosphates to them (phosphorylation) as opposed to kinases which modify lipids, carbohydrates, or other molecules. Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. The human genome contains about 500 protein kinase genes and they constitute about 2% of all human genes. There are two main types of protein kinase.
