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High affinity RGD‐binding sites at the plasma membrane of Arabidopsis thaliana links the cell wall
Author(s) -
Canut Hervé,
Carrasco Antoine,
Galaud JeanPhilippe,
Cassan Catherine,
Bouyssou Huguette,
Vita Natalio,
Ferrara Pascual,
PontLezica Rafael
Publication year - 1998
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1998.00276.x
Subject(s) - plasmolysis , arabidopsis , cell wall , arabidopsis thaliana , biochemistry , membrane , microbiology and biotechnology , chemistry , cell adhesion , integrin , cell , biology , gene , mutant
Summary The heptapeptide Tyr‐Gly‐Arg‐Gly‐Asp‐Ser‐Pro containing the sequenceArg‐Gly‐Asp(RGD – the essential structure recognised by animal cells in substrate adhesion molecules) was tested on epidermal cells of onion and cultured cells of Arabidopsis upon plasmolysis. Dramatic changes were observed on both types of cells following treatment: on onion cells, Hechtian strands linking the cell wall to the membrane were lost, while Arabidopsis cells changed from concave to convex plasmolysis. A control heptapeptide Tyr‐Gly‐Asp‐Gly‐Arg‐Ser‐Pro had no effect on the shape of plasmolysed cells. Protoplasts isolated from Arabidopsis cells agglutinate in the presence of ProNectinF, a genetically engineered protein of 72 kDa containing 13 RGD sequences: several protoplasts may adhere to a single molecule of ProNectinF. The addition of the RGD‐heptapeptide disrupted the adhesion between the protoplasts. Purified plasma membrane from Arabidopsis cells exhibits specific binding sites for the iodinated RGD‐heptapeptide. The binding is saturable, reversible, and two types of high affinity sites (K d1 1 nM, and K d2 40 nM) can be discerned. Competitive inhibition by several structurally related peptides and proteins noted the specific requirement for the RGD sequence. Thus, the RGD‐binding activity of Arabidopsis fulfils the adhesion features of integrins, i.e. peptide specificity, subcellular location, and involvement in plasma membrane‐cell wall attachments.