Biomaterial Database

The alpha 4 beta 1 fibronectin ligands CS-1, Hep II, and RGD induce different intracellular events in B lymphoid cells. Comparison with the effects of the endothelial ligand VCAM-1. 1996

C Domínguez-Jiménez, and P Sánchez-Aparicio, and J P Albar, and A García-Pardo

Departmento de Inmunología, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.

The lymphocyte integrin alpha 4 beta 1 is the receptor for the Hep II domain and CS-1 site in fibronectin (Fn) as well as for VCAM-1. We recently showed that upon activation with anti-beta 1 mAb TS2/16, alpha 4 beta 1 also recognizes the RGD Fn sequence. To determine the physiological role of these multiple interactions, we have now studied some intracellular events induced by "resting" and activated alpha 4 beta 1 binding to its different ligands. Analyses of actin and tubulin reorganization upon adhesion of B lymphoid cells to Fn fragments or VCAM-1 showed that VCAM-1, a 38 kDa fragment (Hep II+CS-1), and the CS-1 synthetic peptide induced formation of transient cytoplasmic projections; however, cells attached to a 58 kDa (Hep II) or 80 kDa (RGD) fragments remained rounded. Using transfilter assays, we showed that VCAM-1, 38 kDa and CS-1 also induced dose-dependent B cell migration mediated by alpha 4 beta 1. Furthermore, these three ligands, but not the 80 kDa fragment or a synthetic peptide (H1) containing a sequence from Hep II shown to bind alpha 4 beta 1, induced tyrosine phosphorylation of a 110 kDa protein. Activation of alpha 4 beta 1 with TS2/16 inhibited the cytoplasmic protrusions and cell migration but did not affect the pattern of phosphorylation. Our results indicate that the various alpha 4 beta 1 ligands induce different cellular responses. Most importantly they show that alpha 4 beta 1 interaction with CS-1 is sufficient to trigger intracellular events in B cells. Furthermore, they suggest a regulation by the activation form of the receptor as well as by the ligand in events involving lymphocyte adhesion and migration.

UI	MeSH Term	Description	Entries
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D002448	Cell Adhesion	Adherence of cells to surfaces or to other cells.	Adhesion, Cell,Adhesions, Cell,Cell Adhesions
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002465	Cell Movement	The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.	Cell Migration,Locomotion, Cell,Migration, Cell,Motility, Cell,Movement, Cell,Cell Locomotion,Cell Motility,Cell Movements,Movements, Cell
D003598	Cytoskeletal Proteins	Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.	Proteins, Cytoskeletal
D005353	Fibronectins	Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.	Cold-Insoluble Globulins,LETS Proteins,Fibronectin,Opsonic Glycoprotein,Opsonic alpha(2)SB Glycoprotein,alpha 2-Surface Binding Glycoprotein,Cold Insoluble Globulins,Globulins, Cold-Insoluble,Glycoprotein, Opsonic,Proteins, LETS,alpha 2 Surface Binding Glycoprotein