An immunosupressive protein supporting embryonic implantation and having an important role in cell proliferation: The Early Pregnancy Factor

Abstract

Early pregnancy factor (EPF), identified as an immunosuppresive protein, can be detected in maternal serum within 6-24 hours of fertilization and is present for at least the first two trimester of pregnancy. Besides pregnancy, EPF is secreted by tumor cells, normal growing cells and active platelets during cell growth and division. It is also required for tumor proliferation and tissue renewal. Seventy per cent of the amino acid sequence of EPF derived from human platelets was determined and except from a single residue, it was identical to the sequence of rat mitochondrial chaperonin 10 (cpn 10). The molecular weight of the protein was found to be 10,843 Da. Whether EPF and cpn 10 are the same molecule or not is still discussed by many researchers. The rosette inhibition test (RIT) which is the most widely used and most reliable assay for EPF detection is not practical for routine utilization since it is laborious, time consuming and sensitive. Recently, it is expected to speed up the EPF studies by investigating novel assay systems that will be more practical than RIT.

Keywords

• Early pregnancy factor (EPF), chaperonin 10 (cpn 10); rosette inhibition test (RIT)

Embriyo implantasyonunu destekleyen ve hücre proliferasyonunda önemli rol oynayan immunosupresif bir protein: Erken Gebelik Faktörü

Abstract

İmmunosupresif özelliğe sahip bir protein olan erken gebelik faktörü (EGF) fertilizasyondan sonra yaklaşık 6-24 saat içerisinde maternal serumda tespit edilebilir ve pek çok canlı türünde gebeliğin ilk iki trimesteri boyunca üretilir. EGF'nin önemi sadece gebelik süreciyle sınırlı değildir. Yapılan çalışmalar EGF'nin tümör hücreleri, normal çoğalan hücreler ve aktif plateletler tarafından hücre büyümesi ve bölünmesi sırasında üretildiğini, tümör hücrelerinin proliferasyonu ve doku yenilenmesi için de gerekli olduğunu göstermiştir. İnsan plateletinden izole edilen ve moleküler ağırlığı 10,843 Da olarak bulunan EGF'nin amino asit sıralamasının yüzde yetmişi belirlenmiş ve tek bir amino asit rezidüsü dışında sıçan mitokondriyal şaperon 10 (cpn 10) ile aynı olduğu tespit edilmiştir. EGF ile cpn 10'un aynı molekül olup olmadığı tartışmaları ise halen devam etmektedir. EGF tespitinde en çok kullanılan ve aynı zamanda en güvenilir test olan "rozet inhibisyon testi" (RIT) zahmetli, zaman alıcı ve hassas olması sebebiyle rutin kullanımda pratik olmamaktadır. Son yıllarda yapılan çalışmalarda EGF aktivitesini ölçmek için RIT'a alternatif yeni yöntemlerin araştırılmasıyla birlikte bu alanda yapılacak çalışmalara hız kazandırılması amaçlanmaktadır.

Keywords

• Erken gebelik faktörü (EGF), şaperon 10 (cpn 10); rozet inhibisyon testi (RIT)

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