Title of article :
The N-End Rule Pathway inXenopusEgg Extracts
Author/Authors :
Davydov، نويسنده , , Ilia V. and Patra، نويسنده , , Debabrata and Varshavsky، نويسنده , , Alexander، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 1998
Pages :
9
From page :
317
To page :
325
Abstract :
Ubiquitin-dependent degradation of intracellular proteins underlies a multitude of biological processes, including the cell cycle, cell differentiation, and responses to stress. One ubiquitin-dependent proteolytic system is the N-end rule pathway, whose targets include proteins that bear destabilizing N-terminal residues. This pathway, which has been characterized only in somatic cells, is shown here to be present also in germ line cells such as the eggs of the amphibianXenopus laevis.We demonstrate that the set of destabilizing residues in the N-end rule pathway ofXenopuseggs is similar, if not identical, to that of somatic cells such as mammalian reticulocytes and fibroblasts. It is also shown that the degradation of engineered N-end rule substrates in egg extracts can be strongly and selectively inhibited by dipeptides bearing destabilizing N-terminal residues. This result allowed us to ask whether selective inhibition of the N-end rule pathway in egg extracts influences the apoptosis-like changes that are observed in these extracts. A dipeptide bearing a bulky hydrophobic (type 2) destabilizing N-terminal residue was found to delay the apoptotic changes in egg extracts, whereas dipeptides bearing basic (type 1) destabilizing N-terminal residues had no effect. High activity of the N-end rule pathway in egg extracts provides an alternative to reticulocyte extracts for thein vitroanalyses of this pathway.
Keywords :
ubiquitin , N-end rule , apoptosis , Proteolysis , Germ line , Xenopus
Journal title :
Archives of Biochemistry and Biophysics
Serial Year :
1998
Journal title :
Archives of Biochemistry and Biophysics
Record number :
1613310
Link To Document :
بازگشت