Table I. Different functions and localizations of TA proteins.
| Function | Examples | Localization |
|---|---|---|
| Enzymatic | Cytochrome b(5) MOM isoform of cytochrome b(5) Heme oxygenase I and II UBC6 |
ER MOM ER ER |
| Protein localization | ||
| Translocation | Sec61γ, Sec61β TOM5, TOM6 Pex15p |
ER MOM Peroxisomes |
| Adaptors | OMP25 | MOM |
| Vesicular traffic | ||
| SNARE proteins | Target SNAREs (Syntaxins) Vesicular SNAREs (e.g., Synaptobrevins) |
Target membranes for vesicular fusion |
| Tethering proteins | Giantin | Transport vesicles Golgi complex |
| Regulation of apoptosis (Bcl-2 family) | Bcl-2 Bcl-XL Bax |
MOM and ER MOM Cystol and MOM |
| Constituent of viral envelope | Us9 protein of α herpes viruses | Trans-Golgi network |