8.A.195.  The Erlin1/2 Complex (Erlin) Family 

The ERLIN1/ERLIN2 complex mediates the endoplasmic reticulum-associated degradation (ERAD) of inositol 1,4,5-trisphosphate receptors (IP3Rs). Involved in regulation of cellular cholesterol homeostasis by regulation the SREBP signaling pathway. The erlin complex binds cholesterol and may promote ER retention of the SCAP-SREBF complex (Huber et al. 2013). It is required early in hepatitis C virus (HCV) infection to initiate RNA replication, and later in the infection to support infectious virus production (Whitten-Bauer et al. 2019). The binding of the erlin1/2 complex to the third intralumenal loop of the inositol triP receptor 1 (IP3R1; TC# 1.A.3.2.6) triggers its ubiquitin-proteasomal degradation (Gao et al. 2022). The Erlin1/2 complex is involved as part of the SV40 ER membrane penitration complex (TC# 1.P.1.1.1).

 

 


This family belongs to the Stomatin/Erlin/Podicin Superfamily.
 

References:

Gao, X., C.G. Bonzerato, and R.J.H. Wojcikiewicz. (2022). Binding of the erlin1/2 complex to the third intralumenal loop of IPR1 triggers its ubiquitin-proteasomal degradation. J. Biol. Chem. 298: 102026. [Epub: Ahead of Print]
Huber, M.D., P.W. Vesely, K. Datta, and L. Gerace. (2013). Erlins restrict SREBP activation in the ER and regulate cellular cholesterol homeostasis. J. Cell Biol. 203: 427-436.
Whitten-Bauer, C., J. Chung, A. Gómez-Moreno, P. Gomollón-Zueco, M.D. Huber, L. Gerace, and U. Garaigorta. (2019). The Host Factor Erlin-1 is Required for Efficient Hepatitis C Virus Infection. Cells 8:.
Examples:

TC#NameOrganismal TypeExample
8.A.195.1.1

The Erlin1/2 complex; Erlin1, 348 aas; Erlin2, 339 aas. See the family description for functions (Gao et al. 2022).

Erlin1/2 of Homo sapiens

 
8.A.195.1.2

Uncharacterized protein of 382 aas and 1 N-terminal TMS.

UP of Cafeteria roenbergensis

 
8.A.195.1.3

Uncharacterized protein of 334 aas and 1 N-terminal TMS.

UP of Endozoicomonas ascidiicola

 
8.A.195.1.4

SPFH domain-containing protein of 415 aas and possibly 3 TMSs, 2 N-terminal and 1 C-terminal.

SPFH domain protein of Solimonas fluminis

 
8.A.195.1.5

Prohibitin family protein of 260 aas and 1 N-terminal TMS.

Prohibitin protein of Staphylococcus pseudintermedius