Signal peptidase complex subunit 3 (SPCS3)

Signal peptidase complex subunit 3 (SPCS3) is an essential non-catalytic component of the endoplasmic reticulum-resident signal peptidase complex (SPC), a serine endopeptidase responsible for the co-translational cleavage of N-terminal signal peptides from newly translocated nascent proteins, enabling their maturation and proper sorting within the secretory pathway[1][3][4][7]. SPCS3 is integral to the stability and functional organization of the SPC, acting to position or stabilize the active center of the enzyme at the luminal surface of the ER[1][7]. Beyond its fundamental housekeeping role in proteostasis, SPCS3 is critical for the proper processing of viral proteins—specifically, it has been shown to be essential for productive virion assembly of several pathogenic flaviviruses, including dengue, Zika, West Nile, and yellow fever viruses[1][3][4]. It is a member of the SPCS3 protein family and is encoded by the human SPCS3 gene located on chromosome 4. Dysfunction or modulation of SPCS3 may impact a wide array of cell processes that depend on secretory and membrane proteins[1][4].

Other names

SPC22SPC22/23SPC3SPase 22/23 kDa subunitMicrosomal signal peptidase 22/23 kDa subunitFLJ22649PRO3567YLR066W

Inhibition or modulation of the signal peptidase complex could hypothetically impair protein maturation and block viral protein processing[3][4].