The signal sequence of the p62 protein of Semliki Forest virus is involved in initiation but not in completing chain translocation

Therefore, we assume that the p62 signal sequence, with its glycosylation site at Asn13, cannot become glycosylated before it has been released into ER lumen. As this glycosylation event was shown to occur at an early stage of chain translocation it follows that this signal sequence can only interact with the ER membrane during the beginning of chain translocation. In other words, the signal sequence of p62 can only function at the initiation stage of chain translocation and has no role in completing this transfer process. If the latter would be true we would have expected that the signal sequence glycosylation would have occurred first after all of the lumenal domain of the p62 d-4 chain would have been translated and translocated.