Dense granule
Encyclopedia
Dense granules are specialized secretory
organelle
s.
protozoa
ns.
They are also found in Entamoeba
.
s contain adenosine diphosphate
(ADP), adenosine triphosphate
(ATP), ionized calcium
which is necessary for several steps of the coagulation cascade, and serotonin
.
can be associated with Hermansky-Pudlak syndrome
.
Secretion
Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product...
organelle
Organelle
In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....
s.
In unicellular organisms
They are found in animals and in unicellular organisms including ApicomplexaApicomplexa
The Apicomplexa are a large group of protists, most of which possess a unique organelle called apicoplast and an apical complex structure involved in penetrating a host's cell. They are unicellular, spore-forming, and exclusively parasites of animals. Motile structures such as flagella or...
protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
ns.
They are also found in Entamoeba
Entamoeba
Entamoeba is a genus of Amoebozoa found as internal parasites or commensals of animals.In 1875, Fedor Lösch described the first proven case of amoebic dysentery in St Petersburg, Russia. He referred to the amoeba he observed microscopically as 'Amoeba coli'; however it is not clear whether he was...
.
Components
The dense granules of human plateletPlatelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days...
s contain adenosine diphosphate
Adenosine diphosphate
Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
(ADP), adenosine triphosphate
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
(ATP), ionized calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
which is necessary for several steps of the coagulation cascade, and serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
.
Clinical significance
A deficiency of CD63CD63
CD63 antigen is a protein that in humans is encoded by the CD63 gene.CD63 is a good marker for flow cytometric quantification of in vitro activated basophils for diagnosis of IgE-mediated allergy. The test is commonly designated as basophil activation test -Interactions:CD63 has been shown to...
can be associated with Hermansky-Pudlak syndrome
Hermansky-Pudlak syndrome
Hermansky–Pudlak syndrome is a rare autosomal recessive disorder which results in oculocutaneous albinism , bleeding problems due to a platelet abnormality , and storage of an abnormal fat-protein compound .There are eight classic forms of the disorder, based on the genetic mutation...
.