title: Binding of the C-terminal sterile alpha motif (SAM) domain of human p73 to lipid membranes.
abstract: The alpha splice variant of p73 (p73alpha), a homologue of the tumor suppressor p53, has close to its C terminus a sterile alpha motif (SAM), SAMp73, that is thought to be involved in protein-protein interactions. Here, we report the lipid binding properties of this domain. Binding was assayed against zwitterionic (phosphatidylcholine) and anionic (phosphatidic acid) lipids and was studied by different biophysical techniques, namely, circular dichroism and fluorescence spectroscopies and differential scanning calorimetry. These techniques unambiguously indicate that SAMp73 binds to lipids. The binding involves protein surface attachment and partial membrane penetration, accompanied by changes in SAMp73 structure.
authors.affiliation: Instituto de Biología Molecular y Celular, Edificio Torregaitán, Universidad Miguel Hernández, Avda. del Ferrocarril s/n, 03202 Elche (Alicante), Spain.
authors.forename: Francisco N
authors.initials: FN
authors.lastname: Barrera
authors.forename: José A
authors.initials: JA
authors.lastname: Poveda
authors.forename: José M
authors.initials: JM
authors.lastname: González-Ros
authors.forename: José L
authors.initials: JL
authors.lastname: Neira
mesh_terms: D020816:Amino Acid Motifs; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D016147:Genes, Tumor Suppressor; D006801:Humans; D008051:Lipid Bilayers / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins
chemical_list: D004268:DNA-Binding Proteins; D008051:Lipid Bilayers; D008565:Membrane Proteins; D009687:Nuclear Proteins; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins