8.A.70 The Endomembrane Morphogenesis TMEM170A (TMEM170A) Family

The TMEM170A protein plays a role in endoplasmic reticulum (ER) and nuclear envelope (NE) morphogenesis (Christodoulou et al. 2016). TMEM170A localizes in ER and NE membranes. Silencing or overexpressing TMEM170A alters ER shape and morphology. Ultrastructural analysis revealed that down-regulation of TMEM170A specifically induced tubular ER formation, while overexpression of TMEM170A induced ER sheet formation. Additionally, down-regulation of TMEM170A altered nuclear shape and size, decreased the density of nuclear pore complexes (NPCs) in the NE and caused either a reduction in inner nuclear membrane (INM) proteins or their relocalization to the ER. TMEM170A interacts with RTN4, a member of the reticulon family; simultaneous co-silencing of TMEM170A and RTN4 rescued ER, NPC and NE-related phenotypes, implying that these two proteins have antagonistic effects on ER membrane organization, NE and NPC formation.



Christodoulou, A., R. Santarella-Mellwig, N. Santama, and I.W. Mattaj. (2016). Transmembrane protein TMEM170A is a novel regulator of ER and NE morphogenesis in human cells. J Cell Sci. [Epub: Ahead of Print]


TC#NameOrganismal TypeExample

TMEM170A intracellular membrane morphogenesis protein of 144 aas and 3 or 4 TMSs (Christodoulou et al. 2016).

TMEM170A of Homo sapiens


Uncharacterized protein of 143 aas and 3 or 4 TMSs.

UP of Caenorhabditis elegans


Transmembrane protein 170, TMEM170, of 227 aas and 4 TMSs.

TMEM170 of Trichinella spiralis (Trichina worm)


Uncharacterized protein of 138 aas and 3 TMSs

UP of Tieghemostelium lacteum


Uncharacterized protein of 142 aas and 3 TMSs.

UP of Tolypocladium ophioglossoides


Uncharacterized protein of 261 aas and 2 - 4 TMSs.

UP of Monosiga brevicollis (Choanoflagellate)