The Origin and Evolution of the Plant Cell Surface: Algal Integrin-Associated Proteins and a New Family of Integrin-Like Cytoskeleton-ECM Linker Proteins.
Bottom Line: The extracellular matrix of scaly green flagellates consists of small organic scales consisting of polysaccharides and scale-associated proteins (SAPs).Gralins are absent from embryophytes.A model for the evolution of the cell surface proteins in Plantae is discussed.
Affiliation: Biozentrum Köln, Botanical Institute, Universität zu Köln, Germany email@example.com.Show MeSH
Mentions: The subcellular localization of SAP126, a member of the large high-molecular weight complex (>2MDa) is known (Becker et al. 1996); however, the localization of the second SAP complex of 190 kDa, which includes SAP98, has not yet been determined. To address this question, the C-terminal part of SAP98 (SAP98-C, 484 amino acids) was expressed in bacteria (not shown). SAP98-C was purified by SDS-PAGE from inclusion bodies and subsequently used for preparation of a polyclonal antibody. On Western blots (fig. 2), the antibody recognized a protein of 98 kDa (80 kDa after deglycosylation with N-Glykosidase F). The apparent molecular mass of the deglycosylated protein (SDS-PAGE) is in very good agreement with the predicted molecular size (79.1 kDa) for SAP98. Immunofluorescence revealed that SAP98 is localized to the flagella (fig. 3). Often the fluorescence was located in two clearly distinguishable rows (fig. 3), suggesting that SAP98 may localize to the basal part of the flagellar hair scales, which are arranged in two opposite rows perpendicular to the plane of flagellar beat (fig. 4A). Attempts to localize the protein at the ultrastructural level were unsuccessful.Fig. 2.—
Affiliation: Biozentrum Köln, Botanical Institute, Universität zu Köln, Germany firstname.lastname@example.org.