Platelet basic protein

PPBP
Identifiers
AliasesPPBP, B-TG1, Beta-TG, CTAP-III, CTAP3, CTAPIII, CXCL7, LA-PF4, LDGF, MDGF, NAP-2, PBP, SCYB7, TC1, TC2, TGB, TGB1, THBGB, THBGB1, pro-platelet basic protein
External IDsOMIM: 121010; MGI: 1888712; GeneCards: PPBP
Available structures
PDBOrtholog search: PDBe RCSB
Orthologs
DatabasesNCBI: entry; OMA: entry
SpeciesHumanMouse
Entrez

5473

57349

Ensembl

ENSG00000163736

ENSMUSG00000029372

UniProt

P02775

Q9EQI5

RefSeq (mRNA)

NM_002704

NM_023785

RefSeq (protein)

NP_002695

NP_076274

Location (UCSC)Chr 4: 73.99 – 73.99 MbChr 5: 90.92 – 90.92 Mb
PubMed search
Wikidata
View/Edit HumanView/Edit Mouse

Platelet basic protein (PBP) is a protein that in humans is encoded by the gene PPBP (previously CXCL7). PBP is a precursor protein that is cleaved into multiple distinct active proteins, notable Connective tissue-activating peptide III (CTAP-III), Beta-thromboglobulin (Beta-TG), Neutrophil-activating peptide 2 (NAP-2), TC-1, and TC-2. PPBP is first translated into the precursor molecule pro-platelet basic protein (PPBP), the first 34 amino acids of which correspond to the signal peptide, while the remaining amino acid residues at positions 35-128 compose PBP.

PBP is a protein that is released in large amounts from platelets following their activation. It stimulates various processes including mitogenesis, synthesis of extracellular matrix, glucose metabolism and synthesis of plasminogen activator.

Connective tissue-activating peptide III

Connective tissue-activating peptide III (CTAP-III), also called Low-affinity platelet factor IV (LA-PF4), is a protein that corresponds to positions 44-128 of PPBP. This protein has mitogenic effects: stimulating DNA synthesis and mitosis. It also triggers prostaglandin E2 secretion and synthesis of hyaluronic acid and sulfated glycosaminoglycan.

Neutrophil-activating peptide 2

Neutrophil-activating peptide 2 (NAP-2) is a chemokine that corresponds to positions 59-128 of PPBP. NAP-2 activates and attracts neutrophils through interaction with the receptors CXCR1 and CXCR2. There are also shorter (and longer) versions of this peptide with similar effects, with NAP-2(1-63) (corresponding to positions 59-121 of PPBP) being the most potent.

TC-1 and TC-2

TC-1 and TC-2 are antimicrobial proteins corresponding to positions 59-126 and 44-126 of the PPBP protein respectively.

β-Thromboglobulin

β-Thromboglobulin (β-TG), or beta-thromboglobulin, is a protein that corresponds to positions 48-128 of PPBP. It is secreted by platelets along with platelet factor 4 and platelet-derived growth factor, and forms a homodimer. Along with platelet factor 4 (PF4), β-TG is one of the best-characterized platelet-specific proteins. β-TG and PF4 are stored in platelet alpha granules and are released during platelet activation. As a result, they are useful markers of platelet activation. β-TG also has multiple biological activities, for instance being involved in maturation of megakaryocytes.

Biological actions

β-TG is a chemoattractant, strongly for fibroblasts and weakly for neutrophils. It is a stimulator of mitogenesis, extracellular matrix synthesis, glucose metabolism, and plasminogen activator synthesis in human fibroblasts.

β-TG also affects megakaryocyte maturation, and thus helps in regulating platelet production.

Clinical uses

Levels of β-TG is used to index platelet activation. It is measured by ELISA in blood plasma or urine, and often in conjunction with PF4.

Influences

β-TG levels may increase with age. It is elevated in diabetes mellitus.

β-TG levels have been found to be increased by treatment with the synthetic estrogen ethinylestradiol, though were not significantly increased by the natural estrogen estradiol valerate. Levels of β-TG have also been found to be increased or unchanged during normal pregnancy.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000163736 – Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000029372 – Ensembl, May 2017
  3. ↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ↑ "Entrez Gene: PPBP pro-platelet basic protein (chemokine (C-X-C motif) ligand 7)".
  6. 1 2 3 4 5 6 7 8 9 10 11 "Platelet basic protein". UniProt consortium. Retrieved 2026-10-08.
  7. ↑ Hristov M, Zernecke A, Bidzhekov K, et al. (March 2007). "Importance of CXC chemokine receptor 2 in the homing of human peripheral blood endothelial progenitor cells to sites of arterial injury". Circ. Res. 100 (4): 590–7. doi:10.1161/01.RES.0000259043.42571.68. PMID 17272812.
  8. ↑ Majumdar S, Gonder D, Koutsis B, Poncz M (1991). "Characterization of the human beta-thromboglobulin gene. Comparison with the gene for platelet factor 4". J Biol Chem. 266 (9): 5785–9. doi:10.1016/S0021-9258(19)67665-9. PMID 1826003.
  9. ↑ Castor C, Miller J, Walz D (1983). "Structural and biological characteristics of connective tissue activating peptide (CTAP-III), a major human platelet-derived growth factor". Proc Natl Acad Sci USA. 80 (3): 765–9. Bibcode:1983PNAS...80..765C. doi:10.1073/pnas.80.3.765. PMC 393460. PMID 6572368.
  10. ↑ Castor C, Furlong A, Carter-Su C (1985). "Connective tissue activation: stimulation of glucose transport by connective tissue activating peptide III". Biochemistry. 24 (7): 1762–7. doi:10.1021/bi00328a029. PMID 4005226.
  11. 1 2 3 Sharma G, Berger JS (August 2011). "Platelet activity and cardiovascular risk in apparently healthy individuals: a review of the data". J Thromb Thrombolysis. 32 (2): 201–8. doi:10.1007/s11239-011-0590-9. PMID 21562837. S2CID 23686294.
  12. ↑ Kaplan KL, Owen J (February 1981). "Plasma levels of beta-thromboglobulin and platelet factor 4 as indices of platelet activation in vivo". Blood. 57 (2): 199–202. doi:10.1182/blood.V57.2.199.199. PMID 6160890.
  13. ↑ Pillai MM, Iwata M, Awaya N, Graf L, Torok-Storb B (May 2006). "Monocyte-derived CXCL7 peptides in the marrow microenvironment". Blood. 107 (9): 3520–6. doi:10.1182/blood-2005-10-4285. PMC 1895768. PMID 16391012.
  14. 1 2 3 Cella G, Scattolo N, Girolami A, Sasahara AA (1984). "Are platelet factor 4 and beta-thromboglobulin markers of cardiovascular disorders?". Ric Clin Lab. 14 (1) 9: 9–18. doi:10.1007/BF02905035. PMID 6203164. S2CID 58519828.
  15. 1 2 3 4 Cytokines & Cells Online Pathfinder Encyclopaedia → Beta-Thromboglobulin Retrieved on August 17, 2009
  16. ↑ Chung-Eun Ha, N. V. Bhagavan (24 April 2015). Essentials of Medical Biochemistry: With Clinical Cases (2 ed.). Academic Press. pp. 652–. ISBN 978-0-12-416697-4. OCLC 1006915388.
  17. ↑ Martinelli I, Bucciarelli P, Mannucci PM (February 2010). "Thrombotic risk factors: basic pathophysiology". Crit Care Med. 38 (2 Suppl): S3–9. doi:10.1097/CCM.0b013e3181c9cbd9. PMID 20083911. S2CID 34486553.
  18. ↑ Page 121 in: Sterne, Jonathan, Kirkwood, Betty R. (2003). Essential medical statistics. Oxford: Blackwell Science. ISBN 0-86542-871-9.
  19. ↑ Farris M, Bastianelli C, Rosato E, Brosens I, Benagiano G (October 2017). "Pharmacodynamics of combined estrogen-progestin oral contraceptives: 2. effects on hemostasis". Expert Rev Clin Pharmacol. 10 (10): 1129–1144. doi:10.1080/17512433.2017.1356718. PMID 28712325. S2CID 205931204.
  20. ↑ Kluft C, Lansink M (July 1997). "Effect of oral contraceptives on haemostasis variables". Thromb Haemost. 78 (1): 315–26. doi:10.1055/s-0038-1657546. PMID 9198173.
  21. ↑ Kuhl H (1998). "Adverse effects of estrogen treatment: natural vs. synthetic estrogens". In Lippert TH, Mueck AO, Ginsburg J (eds.). Sex Steroids and the Cardiovascular System: The Proceedings of the 1st Interdisciplinary Workshop, Tuebingen, Germany, October 1996. London/New York: Parthenon. pp. 201–210. ISBN 9781850709565.
  22. ↑ Lindberg UB, Crona N, Stigendal L, Teger-Nilsson AC, Silfverstolpe G (February 1989). "A comparison between effects of estradiol valerate and low dose ethinyl estradiol on haemostasis parameters". Thromb Haemost. 61 (1): 65–9. doi:10.1055/s-0038-1646528. PMID 2526387.
  23. ↑ Hellgren M (April 2003). "Hemostasis during normal pregnancy and puerperium". Semin Thromb Hemost. 29 (2): 125–30. doi:10.1055/s-2003-38897. PMID 12709915.

Further reading