Procyclins also known as procyclic acidic repetitive proteins or PARP
are
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, res ...
s developed in the surface coating of ''
Trypanosoma brucei
''Trypanosoma brucei'' is a species of parasitic kinetoplastid belonging to the genus '' Trypanosoma'' that is present in sub-Saharan Africa. Unlike other protozoan parasites that normally infect blood and tissue cells, it is exclusively extrace ...
'' parasites while in their
tsetse fly
Tsetse ( , or ) (sometimes spelled tzetze; also known as tik-tik flies), are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus ''Glossina'', which are placed in their own family, Glos ...
vector.
The cell surface of the bloodstream form features a dense coat of
variable surface glycoproteins (VSGs) which is replaced by an equally dense coat of procyclins when the parasite differentiates into the procylic form in the tsetse fly midgut.
There are six or seven procyclin genes that encode unusual proteins with extensive tandem repeat units of
glutamic acid (E) and
proline (P), referred to as EP repeats (
EP1,
EP1-2,
EP2,
EP2-1,
EP3,
EP3-2,
EP3-4), and two genes that encode proteins with internal pentapeptide GPEET repeats (
GPEET2).
EP1 is a 141 amino acids protein and EP2 is a 129 AA protein. Both proteins have their coding genes situated on chromosome 10. GPEET2 is a 114 AA protein and EP3-2 is 123 AA protein with genes situated on chromosome 6.
See also
*
Coat protein (disambiguation) Coat protein may refer to:
* Viral coat protein, a component of the capsid
* Variable surface glycoproteins or procyclins, surface coat proteins of either the bloodstream form or the procyclic form of the parasite ''Trypanosoma brucei''
* COPI, a t ...
References
External links
Kinetoplastid proteins
Parasitic excavates
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