Cell biology

DNA replication

DNA replication: semiconservative copying of DNA at replication forks by helicase, primase, polymerases, and ligase; one origin in bacteria, thousands in eukaryotes; licensed once per cell cycle; ~1000 nt/s bacterial forks, ~20x slower in eukaryotes.

DNA replication initiation

DNA replication initiation: the process by which initiator proteins such as ORC (eukaryotes) and DnaA (bacteria) select replication origins, load MCM2-7 or DnaB helicases, and activate CMG to begin genome duplication exactly once per cell cycle.

DNA replication regulator Sld3

Sld3 (Treslin/TICRR in metazoans) is an essential budding yeast DNA replication initiation protein that binds Cdc45, reads DDK phosphorylation of Mcm4/6, is phosphorylated by CDK at T600/S622 to bind Dpb11, and is inhibited by Rad53 to block late origin firing.

DNA transfection

DNA transfection is a laboratory method that introduces foreign DNA into cultured cells, typically with chemical reagents or electric pulses, to express proteins or study gene function.

Dopaminergic pathways

Dopaminergic pathways are the brain's dopamine neuron projections: nigrostriatal (motor, substantia nigra to dorsal striatum), mesolimbic and mesocortical (VTA to nucleus accumbens and prefrontal cortex, reward and executive function), and tuberoinfundibular (hypothalamus to pituitary, prolactin inhibition).

dTAG

dTAG is a targeted protein degradation method in which a small-molecule ligand recruits an E3 ubiquitin ligase to degrade a protein fused to an FKBP12F36V tag, typically within one to two hours.

Dual staining

Dual staining is a histology and cytology method that detects two different targets, such as antigenic epitopes or RNA sequences, on one tissue section or cell preparation.

Dynein

Dynein: AAA+ microtubule motor proteins moving toward the minus end; cytoplasmic dynein-1 drives cargo transport and spindle assembly, dynein-2 powers intraflagellar transport, axonemal dyneins beat cilia; regulated by dynactin and Lis1.

ECV-304

ECV-304 (CVCL_2029), a human cell line described in 1990 as spontaneously transformed umbilical vein endothelial cells but shown in 1999 to be a T24 bladder carcinoma derivative; ICLAC-00117, still used in endothelial and vasculogenic mimicry studies.

Eisosome component PIL1/LSP1

PIL1 and LSP1 encode the paralogous BAR-domain proteins Pil1 and Lsp1 that form the core of eisosomes, immobile furrow-associated plasma membrane domains in fungi; Pil1 is essential for eisosome assembly while Lsp1 is not.

Electrofusion

Electrofusion is a bench technique using short electric pulses to fuse adjacent cell membranes, producing hybrid cells for monoclonal antibodies, cancer vaccines, and diabetes research.

Electron tomography

Electron tomography is a microscopy method that reconstructs 3D volumes, called tomograms, of cells, organelles, and macromolecular assemblies from tilted image series recorded with a transmission electron microscope.

Electrophysiology recording

Electrophysiology recording is a laboratory technique that measures the electrical activity of living cells, such as neurons, using electrodes to detect membrane voltage or ionic currents.

Electroporation

Electroporation: pulsed electric fields raise cell membrane permeability via nanoscale pores. Reversible forms deliver drugs and DNA (electrochemotherapy, gene electrotransfer); irreversible electroporation ablates tumors nonthermally.

Elysia (gastropod)

Elysia (Risso, 1818) is a genus of sacoglossan sea slugs, about 101 species, famous for kleptoplasty: species such as E. chlorotica, E. timida, E. crispata, and E. viridis retain functional stolen algal chloroplasts for months.

Embryonic fibroblast

An embryonic fibroblast is a fibroblast, a connective-tissue cell that produces extracellular matrix, that is part of an embryo; mouse embryonic fibroblasts are widely used as feeder layers for stem-cell culture.

Endocardial cell

Endocardial cell (CL:0002350), also called endocardial endothelial cell: the endothelial cell lining the heart chambers' inner surface, distinct from coronary endothelium in origin, markers (Npr3, Hapln1, Cdh11), and roles in valves, trabeculation, and cardiomyocyte signaling.

Endocrine cell

Endocrine cell (endocrinocyte, CL:0000163): a secretory cell of a ductless gland that releases hormones directly into the blood. Subtypes include neuroendocrine, enteroendocrine, and the five pancreatic islet cell types.

Endocytosis

Endocytosis: cellular uptake of macromolecules and membrane via vesicles. Also phagocytosis, pinocytosis, clathrin-mediated endocytosis. Pathways include CME (~120 nm vesicles), caveolae (~60 nm), CLIC/GEEC, macropinocytosis; coined by Metchnikoff (1883) and Lewis (1931).

Endomembrane system

Endomembrane system: the eukaryotic network of ER, Golgi apparatus, endosomes, lysosomes, vesicles, nuclear envelope, and plasma membrane that synthesizes, sorts, and transports proteins and lipids.

Endoplasmic reticulum

The endoplasmic reticulum (ER) is a continuous network of membrane-bound tubules and sheets in eukaryotic cells where secreted and membrane proteins are synthesized and folded, most lipids are made, and calcium is stored.

Endoplasmic Reticulum Stress

Endoplasmic reticulum stress (ER stress): disturbance of ER protein folding that activates the unfolded protein response via IRE1, PERK, and ATF6 sensors, restoring homeostasis or triggering apoptosis; linked to diabetes, cancer, and neurodegeneration.

Endoplasmic-reticulum–Golgi intermediate compartment

The endoplasmic-reticulum–Golgi intermediate compartment (ERGIC), also called the vesicular-tubular cluster, is a system of membrane-bounded tubules and vesicles between the ER and Golgi that sorts secretory cargo.

Endosome

Endosome: membrane-bound eukaryotic organelle sorting endocytosed cargo for recycling, retrograde transport, or lysosomal degradation; early (Rab5, pH ~6) to late (Rab7, MVB) maturation, ESCRT sorting, exosome release, immunity and drug delivery roles.

Endothelial cell

Endothelial cell, or EC, the main cell lining blood vessels, lymph vessels, and the heart; forms the endothelium, stores von Willebrand factor in Weibel–Palade bodies, regulates vascular tone, permeability, and angiogenesis, and shows organ-specific heterogeneity.

Endothelial cell apoptotic process

Endothelial cell apoptotic process (GO:0072577), also called endothelial cell apoptosis, is the Gene Ontology term for programmed cell death of endothelial cells, executed via mitochondrial and death receptor caspase pathways and central to vascular remodeling and cardiovascular disease.

Endothelial colony forming cell

Endothelial colony forming cells (ECFCs), also called blood outgrowth endothelial cells or late outgrowth EPCs, are rare circulating endothelial progenitors with clonal proliferative potential that form functional blood vessels in vivo, distinct from myeloid angiogenic cells, and remain preclinical.

Endovascular extravillous trophoblast cell

Endovascular extravillous trophoblast (enEVT, endovascular trophoblast, EndTb): a fetal trophoblast subtype that invades uterine spiral arteries, replaces endothelium, plugs vessels until ~12 weeks, and remodels them 5-10 fold; failure causes preeclampsia and fetal growth restriction.