title: An acidic matrix protein, Pif, is a key macromolecule for nacre formation.
abstract: The mollusk shell is a hard tissue consisting of calcium carbonate crystals and an organic matrix. The nacre of the shell is characterized by a stacked compartment structure with a uniformly oriented c axis of aragonite crystals in each compartment. Using a calcium carbonate-binding assay, we identified an acidic matrix protein, Pif, in the pearl oyster Pinctada fucata that specifically binds to aragonite crystals. The Pif complementary DNA (cDNA) encoded a precursor protein, which was posttranslationally cleaved to produce Pif 97 and Pif 80. The results from immunolocalization, a knockdown experiment that used RNA interference, and in vitro calcium carbonate crystallization studies strongly indicate that Pif regulates nacre formation.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kazuko
authors.initials: K
authors.lastname: Saruwatari
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kogure
authors.forename: Yuya
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nagasawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000737:chemistry* / Q000378:metabolism*; D003460:Crystallization; D018076:DNA, Complementary; D004847:Epithelial Cells / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D049911:Pinctada / Q000737:chemistry / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference
chemical_list: D018076:DNA, Complementary; D011498:Protein Precursors; D011506:Proteins; D002119:Calcium Carbonate