Filensin: a new vimentin-binding, polymerization-competent, and membrane-associated protein of the lens fiber cell
Φόρτωση...
Ημερομηνία
Συγγραφείς
Merdes, A.
Brunkener, M.
Horstmann, H.
Georgatos, S. D.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer-reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Cell Biol
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
We have studied the molecular properties of a 100-kD protein, termed filensin, which we have isolated from porcine lens membranes. Filensin represents a membrane-associated element, resistant to salt and nonionic detergent treatment, and extractable only by alkali or high concentrations of urea. By indirect immunofluorescence and immunoelectron microscopy, this protein can be localized at the periphery of the lens fiber cells. Immunochemical analysis suggests that filensin originates from a larger 110-kD component which is abundantly expressed in lens but not in other tissues. Purified filensin polymerizes in a salt-dependent fashion and forms irregular fibrils (integral of 10 nm in diameter) when reconstituted into buffers of physiological ionic strength and neutral pH. Radiolabeled filensin binds specifically to lens vimentin under isotonic conditions, as demonstrated by affinity chromatography and ligand-blotting assays. By the latter approach, filensin also reacts with a 47-kD peripheral membrane protein of the lens cells. Purified filensin binds to PI, a synthetic peptide modelled after a segment of the COOH-terminal domain of peripherin (a type III intermediate filament protein highly homologous to vimentin), but not to various other peptides including the NH2-terminal headpiece of vimentin and derivatives of its middle (rod) domain. The filensin-PI binding is inhibited by purified lamin B, which is known to interact in vitro with PI (Djabali, K., M.-M. Portier, F. Gros, G. Blobel, and S. D. Georgatos. 1991. Cell. 64:109-121). Finally, limited proteolysis indicates that the filensin-vimentin interaction involves a 30-kD segment of the filensin molecule. Based on these observations, we postulate that the lens fiber cells express a polymerization-competent protein which is tightly associated with the plasma membrane and has the potential to serve as an anchorage site for vimentin intermediate filaments.
Περιγραφή
Λέξεις-κλειδιά
Animals, Cell Fractionation, Chromatography, Affinity, Crystallins/chemistry/isolation & purification/*metabolism, Electrophoresis, Polyacrylamide Gel, Fluorescent Antibody Technique, Hydrogen-Ion Concentration, Intermediate Filament Proteins/metabolism, Lamin Type B, Lamins, *Membrane Glycoproteins, Membrane Proteins/chemistry/isolation & purification/*metabolism, Microscopy, Immunoelectron, *Nerve Tissue Proteins, Nuclear Proteins/metabolism, Peptide Fragments/metabolism, Swine, Trypsin/metabolism, Vimentin/isolation & purification/*metabolism
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/1918147
http://jcb.rupress.org/content/115/2/397.full.pdf
http://jcb.rupress.org/content/115/2/397.full.pdf
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικής