REGULATION OF PRELAMIN-A ENDOPROTEASE ACTIVITY BY PRELAMIN-A

The maturation of lamin A is completed by the endoproteolytic cleavage of its farnesylated precursor protein, prelamin A, In the absence of this cleavage, prelamin A can neither give rise to lamin A nor assembl e into the nuclear lamina, We call the enzyme which catalyzes this end oproteolytic step the 'prelamin A endoprotease'. In this study, we beg in characterization of the regulation of prelamin A endoprotease. In p articular, we address the question as to whether prelamin A endoprotea se activity is constitutive in cells or responds to expression of prel amin A, To do this, me compared the activity of this novel endoproteas e in cells which express prelamin A with those that do not, Our data s hows that the enzymatic activity of prelamin A endoprotease is enhance d by the expression of prelamin A. (C) 1997 Federation of European Bio chemical Societies.