SORTING SIGNALS of PROTEIN TRAFFIC for the Nucleus,  Endomembranes, or Secretion 

SIGNAL

Description

Destination

Protein contains
Nuclear
Localizing
Signal
  located anywhere in polypeptide;
  4 to 8 aa's, nucleoplasmin =
        [n-Pro-Lys-Lys-Lys-Arg-Lys-Val-c]
cytoplasm
to  nucleus
Nucleoplasmin: contains a
 Nuclear Localizing Signal
ER
Signal
  sequence of 6 to 12 aa's
  near N-terminal of mostly non-polar aa's
into
E.R. 
ER Signal  &
ER Retention Signal
ER Retention
Signal
  sequence of 4 aa's, at c-terminal
            LYS-ASP-GLU-LEU-  
within
E.R.
ER Signal &
ER Retention Signal
Golgi
Retention
Signal
  sequence of 20 hydrophobic non-polar aa's
   - forms transmembrane domain
     flanked by basic aa's
into
Golgi
ER Signal &
Golgi Retention Signal
Lysosome
Targeting
  within polypeptide - basic charged aa's -
  leads to covalent links of mannose-6-P
into Lysosome ER Signal &
Lysosomal Targeting Signal
Plasma Membrane   ER signal with stretch of non-polar
  hydrophobic transmembrane domain's
  that anchor it in membrane
Plasma Membrane ER Signal &
hydrophobic domain aa's
Secretion  ER proteins encapsulated into vesicles Secretion ER Signal only