Chemotaxis

receptors Receptor may refer to: *Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a n ...

are expressed in the surface membrane with diverse dynamics, some of them have long-term characteristics as they are determined genetically, others have short-term

moiety Moiety may refer to: Chemistry * Moiety (chemistry), a part or functional group of a molecule ** Moiety conservation, conservation of a subgroup in a chemical species Anthropology * Moiety (kinship), either of two groups into which a society is ...

as their assembly is induced ''

ad hoc Ad hoc is a Latin phrase meaning literally 'to this'. In English, it typically signifies a solution for a specific purpose, problem, or task rather than a generalized solution adaptable to collateral instances. (Compare with '' a priori''.) C ...

'' in the presence of the

ligand In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's ele ...

. The diverse feature of the chemotaxis receptors and ligands provides the possibility to select chemotactic responder cells with a simple

chemotaxis assay Chemotaxis assays are experimental tools for evaluation of chemotactic ability of prokaryotic or eukaryotic cells. A wide variety of techniques have been developed. Some techniques are qualitative - allowing an investigator to approximately determ ...

. By chemotactic selection we can determine whether a still not characterized

molecule A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bio ...

acts via the long- or the short-term receptor pathway. Recent results proved that

chemokines Chemokines (), or chemotactic cytokines, are a family of small cytokines or signaling proteins secreted by cells that induce directional movement of leukocytes, as well as other cell types, including endothelial and epithelial cells. In additi ...

(e.g. IL-8,

RANTES Chemokine (C-C motif) ligand 5 (also CCL5) is a protein which in humans is encoded by the ''CCL5'' gene. The gene has been discovered in 1990 by ''in situ'' hybridisation and it is localised on 17q11.2-q12 chromosome. It is also known as RANTES ...

) are working on long-term chemotaxis receptors, while vasoactive peptides (e.g.

endothelin Endothelins are peptides with receptors and effects in many body organs. Endothelin constricts blood vessels and raises blood pressure. The endothelins are normally kept in balance by other mechanisms, but when overexpressed, they contribute ...

) act more on the short-term ones. Term ''chemotactic selection'' is also used to design a technique which separates

eukaryotic Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bact ...

prokaryotic A prokaryote () is a single-celled organism that lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Greek πρό (, 'before') and κάρυον (, 'nut' or 'kernel').Campbell, N. "Biology:Concepts & Connec ...

cells upon their chemotactic responsiveness to selector ligands.

References

{{cite journal , author=Kohidai L and Csaba G , title=Chemotaxis and chemotactic selection induced with cytokines (IL-8, RANTES and TNF alpha) in the unicellular Tetrahymena pyriformis. , journal=Cytokine , year=1988 , volume=10 , pages=481–6 , doi=10.1006/cyto.1997.0328 , pmid=9702410 , issue=7

External links

Chemotaxis
Cell biology Perception Signal transduction