The direction of protein entry into the proteasome determines the variety of products and depends on the force needed to unfold its two termini.

ABSTRACT: Poorly structured domains in proteins enhance their susceptibility to proteasomal degradation. To learn whether the presence of such a domain near either end of a protein determines its direction of entry into the proteasome, directional translocation was enforced on several proteasome substrates. Using archaeal PAN-20S complexes, mammalian 26S proteasomes, and cultured cells, we identified proteins that are degraded exclusively from either the C or N terminus and some showing no directional preference. This property results from interactions of the substrate's termini with the regulatory ATPase and could be predicted based on the calculated relative stabilities of the N and C termini. Surprisingly, the direction of entry into the proteasome affected markedly the spectrum of peptides relea

SUBMITTER: Berko D 

PROVIDER: S-EPMC5603081 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature