ER signal sequence: The sequence ([n]MLSLRQSIRFFKPATRTLCSSRYLL) is located at the N-terminus and begins with one or more charged amino acids followed by a stretch of 6 to 12 hydrophobic residues. Mitochondrial signal sequence: The sequence ([n]MVAMAMASLQSSMSSLSLSSNSFLGQPLSPITLSPFLQG) is 3 to 70 amino acid long alternating hydrophobic and positively charged amino acids.
ER and mitochondria. The ER and mitochondria are known to interact; so the peptide may be translocated from the ER to the mitochondria. The ER retention signal (KDEL), if present it targets the protein to the ER lumen.
Yes. It can be trafficked to the mitochondria if it does not have the ER retention signal.
