Signal transducer CD24 also known as cluster of differentiation 24 or heat stable antigen CD24 (HSA) is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''CD24''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
CD24 is a
cell adhesion molecule
Cell adhesion molecules (CAMs) are a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion. In essence, CAMs help cells stick to each ...
.
Function
CD24 is a
sialoglycoprotein
A sialoglycoprotein is a combination of sialic acid and glycoprotein, which is, itself, a combination of sugar and protein. These proteins often contain one or more sialyl oligosaccharides that are covalently bound to the rest of the molecule.
Gl ...
expressed at the surface of most
B lymphocyte
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...
s and differentiating
neuroblast
In vertebrates, a neuroblast or primitive nerve cell is a postmitotic cell that does not divide further, and which will develop into a neuron after a migration phase. In invertebrates such as ''Drosophila,'' neuroblasts are neural progenitor cells ...
s. It is also expressed on
neutrophil
Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying in ...
s and neutrophil precursors from the
myelocyte
A myelocyte is a young cell of the granulocytic series, occurring normally in bone marrow (can be found in circulating blood when caused by certain diseases).
Structure
When stained with the usual dyes, the cytoplasm is distinctly basophilic ...
stage onwards. The encoded protein is anchored via a
glycosyl phosphatidylinositol (GPI) link to the cell surface. The protein also contributes to a wide range of downstream signaling networks and is crucial for neural development.
Cross-linking of CD24 on the surface of neutrophils induces
apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...
,
and this appears to be defective in
sepsis
Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...
.
CD24 gene is found on chromosome 6 (6q21) An alignment of this gene's sequence finds genomic locations with similarity on chromosomes 1p36, 3p26, 15q21.3, 20q11.2 and Yq11.222. Whether transcription, and corresponding translation, occurs at each of these other genomic locations needs to be experimentally determined.
References
Further reading
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External links
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Mouse CD Antigen Chartwww.copewithcytokines.de: description of CD24 expression*
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