Platelet factor 4 (PF4) is a small
cytokine belonging to the CXC
chemokine family that is also known as chemokine (C-X-C motif) ligand 4 (CXCL4) . This chemokine is released from
alpha-granules of activated
platelets during platelet aggregation, and promotes blood
coagulation by moderating the effects of
heparin-like molecules. Due to these roles, it is predicted to play a role in
wound repair and
inflammation.[5] It is usually found in a complex with
proteoglycan.
Platelet factor-4 is a 70-amino acid protein that is released from the alpha-granules of activated platelets and binds with high affinity to heparin. Its major physiologic role appears to be neutralization of heparin-like molecules on the endothelial surface of blood vessels, thereby inhibiting local
antithrombin activity and promoting coagulation. As a strong chemoattractant for neutrophils and fibroblasts, PF4 probably has a role in inflammation and wound repair.[5][7]
^O'Donovan N, Galvin M, Morgan JG (1999). "Physical mapping of the CXC chemokine locus on human chromosome 4". Cytogenetics and Cell Genetics. 84 (1–2): 39–42.
doi:
10.1159/000015209.
PMID10343098.
S2CID8087808.
^Warkentin TE (March 2007). "Drug-induced immune-mediated thrombocytopenia--from purpura to thrombosis". The New England Journal of Medicine. 356 (9): 891–3.
doi:
10.1056/NEJMp068309.
PMID17329695.
^Warkentin TE, Makris M, Jay RM, Kelton JG (July 2008). "A spontaneous prothrombotic disorder resembling heparin-induced thrombocytopenia". The American Journal of Medicine. 121 (7): 632–6.
doi:
10.1016/j.amjmed.2008.03.012.
PMID18589060.
Bikfalvi A, Gimenez-Gallego G (February 2004). "The control of angiogenesis and tumor invasion by platelet factor-4 and platelet factor-4-derived molecules". Seminars in Thrombosis and Hemostasis. 30 (1): 137–44.
doi:
10.1055/s-2004-822978.
PMID15034805.
S2CID260320397.
Maione TE, Gray GS, Petro J, Hunt AJ, Donner AL, Bauer SI, et al. (January 1990). "Inhibition of angiogenesis by recombinant human platelet factor-4 and related peptides". Science. 247 (4938): 77–9.
Bibcode:
1990Sci...247...77M.
doi:
10.1126/science.1688470.
PMID1688470.
Han ZC, Bellucci S, Tenza D, Caen JP (April 1990). "Negative regulation of human megakaryocytopoiesis by human platelet factor 4 and beta thromboglobulin: comparative analysis in bone marrow cultures from normal individuals and patients with essential thrombocythaemia and immune thrombocytopenic purpura". British Journal of Haematology. 74 (4): 395–401.
doi:
10.1111/j.1365-2141.1990.tb06325.x.
PMID2140694.
S2CID24529258.
Griffin CA, Emanuel BS, LaRocco P, Schwartz E, Poncz M (1987). "Human platelet factor 4 gene is mapped to 4q12----q21". Cytogenetics and Cell Genetics. 45 (2): 67–9.
doi:
10.1159/000132431.
PMID3622011.
Zhang X, Chen L, Bancroft DP, Lai CK, Maione TE (July 1994). "Crystal structure of recombinant human platelet factor 4". Biochemistry. 33 (27): 8361–6.
doi:
10.1021/bi00193a025.
PMID8031770.
Horne MK (April 1993). "The effect of secreted heparin-binding proteins on heparin binding to platelets". Thrombosis Research. 70 (1): 91–8.
doi:
10.1016/0049-3848(93)90226-E.
PMID8511754.
Kolset SO, Mann DM, Uhlin-Hansen L, Winberg JO, Ruoslahti E (April 1996). "Serglycin-binding proteins in activated macrophages and platelets". Journal of Leukocyte Biology. 59 (4): 545–54.
doi:
10.1002/jlb.59.4.545.
PMID8613703.
S2CID23125881.
1f9r: CRYSTAL STRUCTURE OF PLATELET FACTOR 4 MUTANT 1
1f9s: CRYSTAL STRUCTURE OF PLATELET FACTOR 4 MUTANT 2
1pfm: PF4-M2 CHIMERIC MUTANT WITH THE FIRST 10 N-TERMINAL RESIDUES OF R-PF4 REPLACED BY THE N-TERMINAL RESIDUES OF THE IL8 SEQUENCE. MODELS 1-15 OF A 27-MODEL SET.
1pfn: PF4-M2 CHIMERIC MUTANT WITH THE FIRST 10 N-TERMINAL RESIDUES OF R-PF4 REPLACED BY THE N-TERMINAL RESIDUES OF THE IL8 SEQUENCE. MODELS 16-27 OF A 27-MODEL SET.
1rhp: CRYSTAL STRUCTURE OF RECOMBINANT HUMAN PLATELET FACTOR 4