Abstract
As part of a program to define potential roles for plasminogen activation during development, we have studied the metabolism of plasminogen in the chick embryo. Here we report that: 1) plasminogen is present in significant quantities in the yolk of fertile, unincubated eggs; 2) the zymogen can be translocated intact, from the yolk to the developing embryonic circulation; and 3) de novo synthesis of plasminogen occurs during the early phases of embryonic life. The combination of a reservoir of the zymogen in the yolk and protein biosynthesis thus ensures the availability of a substrate for enzymes which may participate in morphogenetic events occurring throughout embryonic life.
Highlights
The cmmercial sources f orre agent 3 were: L-lyainderhydrofhlorid6e, minoccaproic a c i dc.hloranlne - T and benrmidin ed ihydrochlorlde frcm 4 ldric hT; ritonx-loo anSdoybean trypsi ni nhibito rf r m Sigma; p-nitPophenylguanldobenroate frm ICN Pharmaceuticals ;Flwran embryo
As a preface to subsequent contributions dealing with PA’ in the avian embryo, we report here on the availability and biosynthesis of plasminogen during embryonic development
T h e results presented in this paper demonstrate that: 1) plasminogen is presentin significant quantities in the yolk of fertile, unincubated eggs; 2) the zymogen may be translocated, inacomplexprocess, intact to the developingembryonic circulation; and 3) d e nouo synthesis of plasminogen occurs during embryoniclife
Summary
From the Laboratoryof Chemical Biology, The Rockefeller University, New York, New York 10021. Several lines of evidence suggest that secretion of plasminogen activator, a neutral serine protease which converts plasminogen to plasmin (l), is associated with tissue remodeling [2], destruction of the intercellular matrix [3], and cell migration [4].Since these phenomena abound during embryonic life, we have adopted the working hypothesis that precisely regulated and localized extracellular proteolysis may be involved in the degradative phasesof tissue reconstruction and in the transformation of molecules required for the organization of some cell surface or extracellular structures.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
