Maturation of the mammalian secretome

Table 1 Notable experimental studies in the determination of the secretome

Year	Approach	Organelle	Number of proteins	Comment	Reference
1980	Mutagenesis	Cell-wide	23	First attempt to systematically identify secretory machinery (S. cerevisiae)	[27]
2000	Proteomics	Golgi	93 (588)*	First concerted effort to analyze the Golgi proteome. Cycloheximide treatment used to enrich for Golgi residents	[7]
2003	GFP-tagging	ER	296	Subcellular localization of more than 75% of the yeast proteome was determined using GFP fusions (S. cerevisiae)	[3]
		Golgi/TGN	118
2004	Proteomics	Golgi	151 (421)^†	Improved proteomics technologies allowed more comprehensive identification of proteins	[9]
2006	Functional assay	Cell-wide	130	First genome-wide RNAi screen to search for proteins with a functional involvement in secretion (Drosophila S2 cells)	[26]
2006	Proteomics	ER	229	Proteomics and protein correlation profiling of multiple organelles separated by gradient centrifugation	[14]
		ER-Golgi vesicles	220
		Golgi	67
2006	GFP-tagging	ER	382 (68)^‡	Subcellular localization of 90% of the yeast proteome was determined using GFP fusions (S. pombe)	[4]
		Golgi	156 (68)^‡
2006	Proteomics	ER	832 (405)^§	Most quantitative proteomic characterization of the ER, Golgi and COPI vesicles reported to date	[13]
		Golgi	193 (405)^§

*Mass spectrometry was used to identify only 93 of the 588 unique spots observed on two-dimensional gels. ^†From 421 identified proteins, only 151 were annotated as being either unknown or bona fide Golgi residents. ^‡An additional 68 proteins localized to the ER and Golgi. ^§An additional 405 proteins were identified in both ER and Golgi fractions.

ISSN: 1474-760X