UNIGE document Scientific Article
previous document  unige:8633  next document
add to browser collection

A two-step recognition of signal sequences determines the translocation efficiency of proteins

Bost, S.
Strub, K.
Published in The EMBO journal. 1996, vol. 15, no. 3, p. 468-478
Abstract The cytosolic and secreted, N-glycosylated, forms of plasminogen activator inhibitor-2 (PAI-2) are generated by facultative translocation. To study the molecular events that result in the bi-topological distribution of proteins, we determined in vitro the capacities of several signal sequences to bind the signal recognition particle (SRP) during targeting, and to promote vectorial transport of murine PAI-2 (mPAI-2). Interestingly, the six signal sequences we compared (mPAI-2 and three mutated derivatives thereof, ovalbumin and preprolactin) were found to have the differential activities in the two events. For example, the mPAI-2 signal sequence first binds SRP with moderate efficiency and secondly promotes the vectorial transport of only a fraction of the SRP-bound nascent chains. Our results provide evidence that the translocation efficiency of proteins can be controlled by the recognition of their signal sequences at two steps: during SRP-mediated targeting and during formation of a committed translocation complex. This second recognition may occur at several time points during the insertion/translocation step. In conclusion, signal sequences have a more complex structure than previously anticipated, allowing for multiple and independent interactions with the translocation machinery.
Keywords Amino Acid SequenceAnimalsBase SequenceBiological Transport, ActiveChickensDNA/geneticsEndoplasmic Reticulum, Rough/metabolismFemaleHumansMiceMolecular Sequence DataMutagenesis, Site-DirectedOvalbumin/genetics/metabolismPlasminogen Activator Inhibitor 2/ genetics/ metabolismProlactin/genetics/metabolismProtein Precursors/genetics/metabolismProtein Sorting Signals/ genetics/ metabolismSequence Homology, Amino AcidSerine Proteinase Inhibitors/ genetics/ metabolismSignal Recognition Particle/metabolism
PMID: 8599930
Full text
(ISO format)
BELIN, Dominique et al. A two-step recognition of signal sequences determines the translocation efficiency of proteins. In: EMBO Journal, 1996, vol. 15, n° 3, p. 468-478. https://archive-ouverte.unige.ch/unige:8633

437 hits

0 download


Deposited on : 2010-07-12

Export document
Format :
Citation style :