In molecular biology the MAPEG (Membrane-Associated Proteins in Eicosanoid and Glutathione metabolism) family of
proteins
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, re ...
are a group of membrane associated proteins with highly divergent functions.
Included are the
5-lipoxygenase-activating protein
Arachidonate 5-lipoxygenase-activating protein also known as 5-lipoxygenase activating protein, or FLAP, is a protein that in humans is encoded by the ''ALOX5AP'' gene.
Function
FLAP is necessary for the activation of 5-lipoxygenase and theref ...
(gene FLAP),
leukotriene C4 synthase
Leukotriene C4 synthase is an enzyme that in humans is encoded by the ''LTC4S'' gene.
The protein encoded by this gene, LTC4S (or glutathione S-transferase II) is an enzyme that converts leukotriene A4 and glutathione to create leukotriene C4. Th ...
(), which catalyzes the production of
leukotriene C4
Leukotriene C4 (LTC4) is a leukotriene. LTC4 has been extensively studied in the context of allergy and asthma. In cells of myeloid origin such as mast cells, its biosynthesis is orchestrated by translocation to the nuclear envelope along with co ...
(LTC4) from
leukotriene A4
Leukotriene A4 (LTA4) is a leukotriene
Leukotrienes are a family of eicosanoid inflammation, inflammatory mediators produced in leukocytes by the redox, oxidation of arachidonic acid (AA) and the essential fatty acid eicosapentaenoic acid ...
(LTA4), and
microsomal glutathione S-transferase II () (GST-II), which also produces LTC4 from LTA4.
Another example is
prostaglandin E synthase
Prostaglandin E synthase (, or PGE synthase) is an enzyme involved in eicosanoid and glutathione metabolism, a member of MAPEG family. It generates prostaglandin E (PGE) from prostaglandin H2.
The synthase generating PGE2 is a membrane-associate ...
. This enzyme catalyses the synthesis of PGE2 from PGH2 (produced by
cyclooxygenase
Cyclooxygenase (COX), officially known as prostaglandin-endoperoxide synthase (PTGS), is an enzyme (specifically, a family of isozymes, ) that is responsible for biosynthesis of prostanoids, including thromboxane and prostaglandins such a ...
from
arachidonic acid
Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega−6 fatty acid 20:4(ω−6), or 20:4(5,8,11,14). It is a precursor in the formation of leukotrienes, prostaglandins, and thromboxanes.
Together with omega−3 fatty acids an ...
). Because of structural similarities in the active sites of FLAP, LTC4 synthase, and PGE synthase, substrates for each enzyme can compete with one another and modulate synthetic activity.
Subfamilies
*5-lipoxygenase-activating protein
Human proteins containing this domain
*
5-lipoxygenase-activating protein
Arachidonate 5-lipoxygenase-activating protein also known as 5-lipoxygenase activating protein, or FLAP, is a protein that in humans is encoded by the ''ALOX5AP'' gene.
Function
FLAP is necessary for the activation of 5-lipoxygenase and theref ...
(ALOX5AP))
*
LTC4S
Leukotriene C4 synthase is an enzyme that in humans is encoded by the ''LTC4S'' gene.
The protein encoded by this gene, LTC4S (or glutathione S-transferase II) is an enzyme that converts leukotriene A4 and glutathione to create leukotriene C4. Th ...
*
MGST1
Microsomal glutathione S-transferase 1 is an enzyme that in humans is encoded by the ''MGST1'' gene.
Function
The MAPEG family (Membrane-Associated Proteins in Eicosanoid and Glutathione metabolism) consists of six human proteins, two of which ...
*
MGST2
Microsomal glutathione S-transferase 2 is an enzyme that in humans is encoded by the ''MGST2'' 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 ...
*
MGST3
Microsomal glutathione S-transferase 3 is an enzyme that in humans is encoded by the ''MGST3'' gene.
The MAPEG (Membrane-Associated Proteins in Eicosanoid and Glutathione metabolism) family consists of six human proteins, several of which are inv ...
*
PTGES
Microsomal prostaglandin E synthase-1 (mPGES-1) or Prostaglandin E synthase is an enzyme that in humans is encoded by the ''PTGES'' gene.
The protein encoded by this gene is a glutathione-dependent prostaglandin E synthase. The expression of thi ...
References
{{InterPro content, IPR001129
Protein domains
Protein families