EYE2, a thioredoxin-family protein, localizes to the chloroplast envelope compartment of the eyespot, likely directing the site for assembly of the eyespot pigment granule arrays (Boyd et al. 2011a).
Quantitation of differential membrane protein abundance across different cell-envelope compartments, or even under different cellular states, can be achieved using fluorescent protein-reactive dyes before 2D-PAGE.
Transport of proteins across the cell-envelope compartments is essential for bacterial life and in Gram-negative species it can be mediated by at least six different secretion systems (SSs) (Saier, 2006).
In the following section, we provide a summary of the most commonly used proteomic tools in an attempt to investigate the extent of PPIs between the components of various cell-envelope compartments.
In the case of E. coli, these include c. 900 transmembrane proteins spanning the IM (hereafter called TIMPs) and c. 90 spanning the OM (hereafter called TOMPs) (see The E. coli cell-envelope compartments and their associated proteomes section).
2D LC separations exploiting both the net solution charge state and the hydrophobicity of peptides can further boost the detection sensitivity of low-abundance membrane-bound proteins present in the cell-envelope compartments.
The dominant proteins in the envelope and cytoplasmic compartments of H. mustelae were identified by LC-MS.
Thus, inner membrane invaginations may provide a route for the exchange of lipids and proteins between the chloroplast envelope and thylakoid compartments.
In addition to viral tegument proteins and envelope glycoproteins, this compartment also accumulates TGN markers (i.e., TGN46), redistributed early endosomal markers (i.e., EEA1, annexin I), and cargo molecules that travel via the early endosomal route (i.e., M6PR, HRS) and the recycling route (i.e., TfR,).
The chloroplast has several interior compartments: the envelope membranes, the thylakoid membranes and lumen, the stroma and plastoglobules.
Many MAPs regulated by Aurora-A and involved in spindle assembly (TPX2, NuMA, RHAMM, TACC3) are nuclear in interphase and recruited after reorganization of the different compartments (nuclear envelope, endogenous membrane structures).
