Dermal filler complications and management
Michael Parker, Charlie James in Fundamentals for Cosmetic Practice, 2022
Degranulation is, in essence, the release of said granular contents from within a cell to its surrounding environment. Regarding anaphylaxis, the mechanism of release is through a tyrosine-kinase phosphorylation cascade after a pro-inflammatory cell (such as a mast cell) has been activated by an IgE-antigen complex. The relevance of a phosphorylation cascade is that through enzymatic phosphorylation a small signal can be rapidly and significantly amplified via a short series of chemical reactions. This phosphorylation cascade results in an influx in intracellular calcium, which in itself is the trigger for degranulation to occur. When mast cells degranulate, they release pro-inflammatory mediators such as histamine, prostaglandin and cytokines such as TNF-α. See Figure 13.5.
Biochemical Adaptations to Early Extrauterine Life
Emilio Herrera, Robert H. Knopp in Perinatal Biochemistry, 2020
Immediately after delivery, the fall in the insulin/glucagon ratio triggers liver glycogenolysis in order to supply neonatal tissues with glucose for both general and specific purposes (see Section II). Activation of glycogenolysis is achieved by phosphorylation of glycogen phosphorylase through the phosphorylation cascade that is switched on by the increase in cAMP levels (Figure 3). It is very intriguing, however, that the synthesis of glucose 6-phosphatase, a compulsory enzyme for the output of glucose from liver glycogen, is delayed in the rat, being fully active at the middle of the suckling period.12 Since glycogenolysis is very active 2 h after delivery (Figure 4) other enzymes would be responsible for early postnatal glycogenolysis. This may be the case of lysosomal α-glycosidase which has been claimed to be involved in neonatal glycogenolysis.6
Participation of Cytokines and Growth Factors in Biliary Epithelial Proliferation and Mito-Inhibition during Ductular Reactions
Gianfranco Alpini, Domenico Alvaro, Marco Marzioni, Gene LeSage, Nicholas LaRusso in The Pathophysiology of Biliary Epithelia, 2020
KGF binds to the KGF receptor (KGFR), a splice variant of the FGF receptor-2. Like other FGF receptors, KGFR is a transmembrane tyrosine kinase, which contains immunoglobulin-like domains in its extracellular portion and an intracellular tyrosine kinase domain.148 Binding of KGF to its receptor initiates a phosphorylation cascade that leads to activation of phospholipase C-γ and mitogen-activated protein kinase (MAPK).
Advances, challenges and tools in characterizing bacterial serine, threonine and tyrosine kinases and phosphorylation target sites.
Published in Expert Review of Proteomics, 2019
Giovanni J. Pagano, Ryan J. Arsenault
Much like the two-component system, the phosphotransferase system (PTS) involves a series of phosphate transfers between enzymes, allowing for the transport of sugars across the cell membrane. Phosphoenolpyruvate (PEP) first provides a phosphate group to a histidine on the cytosolic protein Enzyme I (EI), which then transfers the phosphate to a histidine on cytosolic HPr. This is followed by the phosphorylation cascade of proteins in the Enzyme II (EII) system, generally EIIA, EIIB and membrane-bound EIIC. The terminal step transfers the phosphate to a sugar for transport into the cell, where it can be metabolized. EI and HPr are general components utilized for all transfers, while the Enzyme II system components are specific for single sugars or small families of carbohydrates [8].
Overcoming challenges in developing small molecule inhibitors for GPVI and CLEC-2
Published in Platelets, 2021
Foteini-Nafsika Damaskinaki, Luis A. Moran, Angel Garcia, Barrie Kellam, Steve P. Watson
The clustering of GPVI and CLEC-2 drives intracellular signaling cascades that lead to activation of platelets. GPVI is a single transmembrane protein belonging to the immunoglobulin family of receptors that is expressed in the membrane with the dimeric Fc receptor (FcR) γ-chain, with each chain having an immunoreceptor tyrosine-based activation motif (ITAM), characterized by two conserved YxxL sequences [29]. In contrast, the single transmembrane, lectin-like receptor, CLEC-2, has one YxxL sequence in its cytosolic tail, named a hemITAM (or hemi-ITAM) [30]. Clustering of GPVI or CLEC-2 leads to phosphorylation of the conserved tyrosines in the hemITAM or ITAM sequence by Src and Syk tyrosine kinases, leading to binding of the tandem SH2 domains in Syk and initiation of a downstream signaling cascade orchestrated through the protein adapter LAT. This acts as a binding template for other proteins facilitating a phosphorylation cascade, including various adapter and effector proteins, leading to activation of PI 3-kinase and PLCγ2 (Figure 1). PI 3-kinase generates the second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) which binds to pleckstrin homology and SH2 domains. PLCγ2 generates the second messenger inositol 1,4, 5-trisphosphate (IP3) and 1,2-diacylglycerol, which release Ca2+ and activate protein kinase C, respectively.
Where the rubber hits the road: Neuroscience and social work
Published in Social Work in Health Care, 2018
The scientist’s background in biochemistry and science education research is the basis for her inquiries into how university students (including social work students), who are commonly referred to as non- science majors (NSM), often hold inadequate conceptions of science (Bergère, 2011). The scientific aspects of her work involved biomolecular and cellular processes associated with physiology of the male reproductive system. Her investigations into how certain proteins, which in this case are enzymes, are modified in vitro by cellular signals between active (ON) and inactive (OFF) states via classical phosphorylation cascade mechanisms (Taylor, Oda & Lingwood, 1987). She was able to indirectly localize the active biomolecules to identify specific developmental cell types in which the products of the pathway appeared during meiotic cell division (Taylor, Oda & Lingwood, 1987).
Related Knowledge Centers
- Conformational Change
- Signal Transduction
- Phosphorylation
- Extracellular Matrix
- Mitogen-Activated Protein Kinase