Abstract
The signal peptides, present at the N-terminus of many proteins, guide the proteins into cell membranes. In some proteins, the signal peptide is with an extended N-terminal region. Previously, it was demonstrated that the N-terminally extended signal peptide of the human PTPRJ contains a cluster of arginine residues, which attenuates translation. The analysis of the mammalian orthologous sequences revealed that this sequence is highly conserved. The PTPRJ transcripts in placentals, marsupials, and monotremes encode a stretch of 10-14 arginine residues, positioned 11-12 codons downstream of the initiating AUG. The remarkable conservation of the repeated arginine residues in the PTPRJ signal peptides points to their key role. Further, the presence of an arginine cluster in the extended signal peptides of other proteins (E3 ubiquitin-protein ligase, NOTCH3) is noted and indicates a more general importance of this cis-acting mechanism of translational suppression.
Highlights
After the start of translation, translation inhibition due to the interaction between the nascent polypeptide chain and the ribosome is reported [1, 2]
The human PTPRJ is a receptor-like protein tyrosine phosphatase of the R3 subtype characterized by an extracellular region, containing several tandem fibronectin type III (FNIII) domains, a single transmembrane region, and a single cytoplasmic catalytic domain [6]
To elucidate the importance of these findings it was of interest to examine the PTPRJ transcripts in mammals for sequences encoding the attenuating arginine-rich cluster
Summary
After the start of translation, translation inhibition due to the interaction between the nascent polypeptide chain and the ribosome is reported [1, 2]. In a limited number of proteins, the signal peptides are longer than the canonical 20–25 residues; they consist of more than forty amino acid residues and contain an N-terminal extension and a hydrophobic sequence (h-region) far from the N-terminus [5]. The human receptor-like protein tyrosine phosphatase, type J (PTPRJ, PTPReta, or DEP1) provides an example of the presence of a down-regulating sequence within the signal peptide. To elucidate the importance of these findings it was of interest to examine the PTPRJ transcripts in mammals for sequences encoding the attenuating arginine-rich cluster.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
