A Shotgun Proteomic
Approach Reveals That Fe Deficiency
Causes Marked Changes in the Protein Profiles of Plasma Membrane and
Detergent-Resistant Microdomain Preparations from <i>Beta vulgaris</i> Roots
In the present study we have used
label-free shotgun proteomic
analysis to examine the effects of Fe deficiency on the protein profiles
of highly pure sugar beet root plasma membrane (PM) preparations and
detergent-resistant membranes (DRMs), the latter as an approach to
study microdomains. Altogether, 545 proteins were detected, with 52
and 68 of them changing significantly with Fe deficiency in PM and
DRM, respectively. Functional categorization of these proteins showed
that signaling and general and vesicle-related transport accounted
for approximately 50% of the differences in both PM and DRM, indicating
that from a qualitative point of view changes induced by Fe deficiency
are similar in both preparations. Results indicate that Fe deficiency
has an impact in phosphorylation processes at the PM level and highlight
the involvement of signaling proteins, especially those from the 14–3–3
family. Lipid profiling revealed Fe-deficiency-induced decreases in
phosphatidic acid derivatives, which may impair vesicle formation,
in agreement with the decreases measured in proteins related to intracellular
trafficking and secretion. The modifications induced by Fe deficiency
in the relative enrichment of proteins in DRMs revealed the existence
of a group of cytoplasmic proteins that appears to be more attached
to the PM in conditions of Fe deficiency