The fate of prorenin during granulopoiesis in epithelioid cells. Immunocytochemical experiments with antisera against XXXX and different portions of the @entity916 prosegment.

@entity1 @entity4223 @entity2733 @entity15621 @entity916 @entity1473
Comparative immunocytochemical experiments with antisera directed against @entity916 and three synthetical peptides ( @entity4223 , Pro 2A and @entity15621 ) covering almost the entire span of @entity1 @entity916 prosegment were performed on @entity1 kidney tissue. With anti- @entity4223 , i.e. the antiserum which recognizes the @entity2733 terminus of @entity1 prorenin, no clear immunolabeling of juxtaglomerular epithelioid cell secretory granules could be obtained. It is therefore concluded that the corresponding portion of @entity1 prorenin may be cleaved off in the Golgi complex. After application of anti- @entity15621 , the antiserum which recognizes the @entity1473 terminus of the prosegment, only the juvenile secretory granules of epithelioid cells were consistently labeled, whereas, in contrast, some of the intermediate and most of the mature secretory granules were anti- @entity15621 -negative. As the immunoreactivity of mature @entity916 increased remarkably from protogranules to mature secretory granules, it is suggested that the cleavage of the @entity1473 terminus of the prosegment, i.e. the activation of @entity916 , takes place in juvenile and intermediate granules during condensation of the enzyme. The immunoreactivity of Pro 2A, corresponding to the middle portion of the prosegment, disappeared in a somewhat earlier stage of granulopoiesis than that of @entity15621 . It is therefore concluded that the corresponding segmental cleavage, the result of which is a truncated version of intact prorenin, occurs in the protogranules of epithelioid cells.(ABSTRACT TRUNCATED AT 250 WORDS)
