The chlamydial inclusion membrane is extensively modified by the insertion of type III secreted effector proteins [1]. These inclusion membrane proteins (Incs) have two major characteristics: an N-terminal type III secretion signal that is necessary for their secretion out of the bacterium and a hydrophobic region consisting of at least two trans-membrane helices that allows insertion into the inclusion membrane. Generally, both the N- and C-terminal regions of the Inc are exposed to the host cell cytosol [2]. This family has members such as the IncD proteins found in Chlamydia trachomatis. This C. trachomatis effector protein IncD has been shown to recruit the lipid transfer protein CERT to the inclusion membrane by directly interacting with CERT PH domain, which mediates the FFAT motif-dependent recruitment of the ER-resident protein VAPB (vesicle-associated membrane protein-associated protein) to the inclusion [3].

1: Role for chlamydial inclusion membrane proteins in inclusion membrane structure and biogenesis. Mital J, Miller NJ, Dorward DW, Dooley CA, Hackstadt T; PLoS One. 2013;8:e63426. PMID:23696825

2: Characterization of interactions between inclusion membrane proteins from Chlamydia trachomatis. Gauliard E, Ouellette SP, Rueden KJ, Ladant D; Front Cell Infect Microbiol. 2015;5:13. PMID:25717440

3: Chlamydiae interaction with the endoplasmic reticulum: contact, function and consequences. Derre I; Cell Microbiol. 2015;17:959-966. PMID:25930206