title: LPP, an actin cytoskeleton protein related to zyxin, harbors a nuclear export signal and transcriptional activation capacity.
abstract: The LPP gene is the preferred translocation partner of the HMGIC gene in a subclass of human benign mesenchymal tumors known as lipomas. Here we have characterized the LPP gene product that shares 41% of sequence identity with the focal adhesion protein zyxin. LPP localizes in focal adhesions as well as in cell-to-cell contacts, and it binds VASP, a protein implicated in the control of actin organization. In addition, LPP accumulates in the nucleus of cells upon treatment with leptomycin B, an inhibitor of the export factor CRM1. The nuclear export of LPP depends on an N-terminally located leucine-rich sequence that shares sequence homology with well-defined nuclear export signals. Moreover, LPP displays transcriptional activation capacity, as measured by GAL4-based assays. Altogether, these results show that the LPP protein has multifunctional domains and may serve as a scaffold upon which distinct protein complexes are assembled in the cytoplasm and in the nucleus.
authors.affiliation: Laboratory for Molecular Oncology, Center for Human Genetics, University of Leuven and Flanders Interuniversity Institute for Biotechnology, B-3000 Leuven, Belgium.
authors.forename: M M
authors.initials: MM
authors.lastname: Petit
authors.forename: J
authors.initials: J
authors.lastname: Fradelizi
authors.forename: R M
authors.initials: RM
authors.lastname: Golsteyn
authors.forename: T A
authors.initials: TA
authors.lastname: Ayoubi
authors.forename: B
authors.initials: B
authors.lastname: Menichi
authors.forename: D
authors.initials: D
authors.lastname: Louvard
authors.forename: W J
authors.initials: WJ
authors.lastname: Van de Ven
authors.forename: E
authors.initials: E
authors.lastname: Friederich
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D019677:Artificial Gene Fusion; D001665:Binding Sites; D018938:Caco-2 Cells; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D015870:Gene Expression; D006023:Glycoproteins; D018922:HL-60 Cells; D006367:HeLa Cells; D006609:High Mobility Group Proteins / Q000235:genetics; D006801:Humans; D060588:LIM Domain Proteins; D018374:LLC-PK1 Cells; D008667:Metalloproteins / Q000737:chemistry; D051379:Mice; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D021382:Protein Sorting Signals; D011817:Rabbits; D013552:Swine; D015533:Transcriptional Activation; D014709:Vero Cells; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D005231:Fatty Acids, Unsaturated; D006023:Glycoproteins; D006609:High Mobility Group Proteins; D060588:LIM Domain Proteins; C103594:LPP protein, human; C491227:Lpp protein, mouse; D008667:Metalloproteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D021382:Protein Sorting Signals; C092842:ZYX protein, human; C498285:Zyx protein, mouse; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein; C038753:leptomycin B