title: The pH sensibility of actin-bundling LIM proteins is governed by the acidic properties of their C-terminal domain.
abstract: Actin-bundling Arabidopsis LIM proteins are subdivided into two subfamilies differing in their pH sensitivity. Widely-expressed WLIMs are active under low and high physiologically-relevant pH conditions, whereas pollen-enriched PLIMs are inactivated by pH values above 6.8. By a domain swapping approach we identified the C-terminal (Ct) domain of PLIMs as the domain responsible for pH responsiveness. Remarkably, this domain conferred pH sensitivity to LIM proteins, when provided "in trans" (i.e., as a single, independent, peptide), indicating that it operates through the interaction with another domain. An acidic 6xc-Myc peptide functionally mimicked the Ct domain of PLIMs and efficiently inhibited LIM actin bundling activity under high pH conditions. Together, our data suggest a model where PLIMs are regulated by an intermolecular interaction between their acidic Ct domain and another, yet unidentified, domain.
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Danièle
authors.initials: D
authors.lastname: Moes
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Céline
authors.initials: C
authors.lastname: Hoffmann
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Monika
authors.initials: M
authors.lastname: Dieterle
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Flora
authors.initials: F
authors.lastname: Moreau
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Katrin
authors.initials: K
authors.lastname: Neumann
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Jessica
authors.initials: J
authors.lastname: Papuga
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: Angela Tavares
authors.initials: AT
authors.lastname: Furtado
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg.
authors.forename: André
authors.initials: A
authors.lastname: Steinmetz
authors.affiliation: Department of Oncology, Luxembourg Institute of Health (L.I.H.), L-1526 Luxembourg, Luxembourg. Electronic address: clement.thomas@lih.lu.
authors.forename: Clément
authors.initials: C
authors.lastname: Thomas
mesh_terms: D000199:Actins / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006863:Hydrogen-Ion Concentration; D060588:LIM Domain Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011058:Pollen / Q000235:genetics; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016271:Proto-Oncogene Proteins c-myc / Q000737:chemistry; D017384:Sequence Deletion
chemical_list: D000199:Actins; D029681:Arabidopsis Proteins; D060588:LIM Domain Proteins; D020033:Protein Isoforms; D016271:Proto-Oncogene Proteins c-myc
keywords: Actin-bundling; Cytoskeleton; LIM domain; c-Myc; pH responsiveness