Nuclear localization signals (NLS) are short cluster of positively charged residues containing lysine (K) and arginine (R) residues.

Membrane proteins

A stretch of hydrophobic residues may signal a transmembrane domain.

Mitochondrial Proteins

The N-terminus has mitochondrial targeting signals.

Peroxisomal proteins

SKL motif: the C-terminal three residues (S/A/C)(K/R/H)L are peroxisomal sorting signal. Many peroxisomal proteins however do not have this motif at the C-terminal.

Chloroplast proteins

Chloroplast proteins have cleavable signals in the N-terminus, which are rich in alanine and serine residues in the N-terminal 30 residues.

ER (endoplasmic reticulum) proteins

ER proteins have the sequence motif KDEL in the C-terminus as retention signal. In yeast and plants, the consensus motif is HDEL.

Vesicular pathway

NPXY and YXRF are signals for coated-pit mediated endocytosis.