Cotton fiber is an ideal model for studying plant cell elongation. To date, the underlying mechanisms controlling fiber elongation remain unclear due to their high complexity. In this study, a comparative proteomic analysis between a short-lint fiber mutant (Ligon lintless, Li1) and its wild-type was performed to identify fiber elongation-related proteins. By 2-DE combined with local EST database-assisted MS/MS analysis, 81 differentially expressed proteins assigned to different functional categories were identified from Li1 fibers, of which 54 were down-regulated and 27 were up-regulated. Several novel aspects regarding cotton fiber elongation can be illustrated from our data. First, over half of the down-regulated proteins were newly identified at the protein level, which is mainly involved in protein folding and stabilization, nucleocytoplasmic transport, signal transduction, and vesicular-mediated transport. Second, a number of cytoskeleton-related proteins showed a remarkable decrease in protein abundance in the Li1 fibers. Accordingly, the architecture of actin cytoskeleton was severely deformed and the microtubule organization was moderately altered, accompanied with dramatic disruption of vesicle trafficking. Third, the expression of several proteins involved in unfolded protein response (UPR) was activated in Li1 fibers, indicating that the deficiency of fiber cell elongation was related to ER stress. Collectively, these findings significantly advanced our understanding of the mechanisms associated with cotton fiber elongation.

We attempted to identify membrane proteins associated with the glycoconjugates and cell wall biosynthesis in the total membrane preparations of Aspergillus fumigatus. The total membrane preparations were first run on 1D gels, and then the stained gels were cut and submitted to in-gel digestion followed by 2D LC-MS/MS and database search. A total of 530 proteins were identified with at least two peptides detected with MS/MS spectra. Seventeen integral membrane proteins were involved in N-, O-glycosylation or GPI anchor biosynthesis. Nine membrane proteins were involved in cell wall biosynthesis. Eight proteins were identified as enzymes involved in sphingolipid synthesis. In addition, the proteins involved in cell wall and ergosterol biosynthesis can potentially be used as antifungal drug targets. Our method, for the first time, clearly provided a global view of the membrane proteins associated with glycoconjugates and cell wall biosynthesis in the total membrane proteome of A. fumigatus.