Pancreatic Stone Protein (PSP), also known as Lithostathine-1-alpha islet cells regeneration factor (ICRF) or islet of Langerhans regenerating protein (REG) is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''REG1A''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
as a single polypeptide of 144 amino acids further cleaved by trypsin to produce a 133 amino acid protein that is O-linked glycosylated on threonine 27. This protein is a type I subclass member of the
Regenerating protein family. The Reg protein family is a multi protein family grouped into four subclasses, types I, II, III and IV based on the primary structures of the proteins.
Reg family members
REG1B,
REGL,
PAP and this gene are tandemly clustered on chromosome 2p12 and may have arisen from the same ancestral gene by gene duplication.
The PSP is mostly produced in Human by the acinar cells of the
pancreas
The pancreas (plural pancreases, or pancreata) is an Organ (anatomy), organ of the Digestion, digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity, abdomen behind the stomach and functions as a ...
and is secreted in the duodenum by the same pathway that pancreatic exocrine enzymes. It has C-terminal
C-type lectin domain
A C-type lectin (CLEC) is a type of carbohydrate-binding protein known as a lectin. The C-type designation is from their requirement for calcium for binding. Proteins that contain C-type lectin domains have a diverse range of functions including c ...
whose binding partner is currently unknown.
Function
Pancreas development and regeneration
The PSP has been shown to be associated with
islet cell regeneration
Regeneration may refer to:
Science and technology
* Regeneration (biology), the ability to recreate lost or damaged cells, tissues, organs and limbs
* Regeneration (ecology), the ability of ecosystems to regenerate biomass, using photosynthesis
...
and
diabetogenesis and may be involved in pancreatic
lithogenesis (creation of
pancreatic stones;
pancreatic calculi).
Sepsis
The blood PSP concentration has been shown to increase substantially in response to a
sepsis
Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.
This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...
event. Consequently, the use of the PSP as a biomarker of sepsis has been investigated thoroughly and the result of these researches confirmed the high diagnostic accuracy of the PSP for sepsis.
Of particular interest, PSP concentration has been shown to increase early in the development of a septic event, as illustrated in a cohort of severely burnt patients
References
Further reading
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