Science Gateway > Protocols > Cell Biology Protocols - Table of Contents
Star Republic: Guide for Biologists

Protein localization signals

Edited by Chang Zhu
Nuclear Localization Signals

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

Gene NLS
SV40 PKKKRKV
H2B GKKRSKV
v-Jun KSRKRKL
Nucleoplasmin KRPAATKKAGQAKKKKLDK
NIN2 RKKRKTEEESPLKDKAKKSK
SWI5 KKYENVVIKRSPRKRGRPRK

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.