title: Isolation of protein-tyrosine phosphatase-like member-a variant from cementum.
abstract: Cementum has been shown to contain unique polypeptides that participate in cell recruitment and differentiation during cementum formation. We report the isolation of a cDNA variant for protein-tyrosine phosphatase-like (proline instead of catalytic arginine) member-a (PTPLA) from cementum. A cementifying fibroma-derived λ-ZAP expression library was screened by panning with a monoclonal antibody to cementum attachment protein (CAP), and 1435 bp cDNA (gb AC093525.3) was isolated. This cDNA encodes a 140-amino-acid polypeptide, and its N-terminal 125 amino acids are identical to those of PTPLA. This isoform, designated as PTPLA-CAP, results from a read-through of the PTPLA exon 2 splice donor site, truncating after the second putative transmembrane domain. It contains 15 amino acids encoded within the intron between PTPLA exons 2 and 3, which replace the active site for PTPLA phosphatase activity. The recombinant protein, rhPTPLA-CAP, has Mr 19 kDa and cross-reacts with anti-CAP antibody. Anti-rhPTPLA-CAP antibody immunostained cementum cells, cementum, heart, and liver. Quantitative RT-PCR showed that PTPLA was expressed in all periodontal cells; however, PTPLA-CAP expression was limited to cementum cells. The rhPTPLA-CAP promoted gingival fibroblast attachment. We conclude that PTPLA-CAP is a splice variant of PTPLA, and that, in the periodontium, cementum and cementum cells express this variant.
authors: Laboratorio de Biología Periodontal y Tejidos Mineralizados, Facultad de Odontología, Universidad Nacional Autónoma de México, México.
authors: A
authors: A
authors: Valdés De Hoyos
authors: L
authors: L
authors: Hoz-Rodríguez
authors: H
authors: H
authors: Arzate
authors: A S
authors: AS
authors: Narayanan
mesh_terms: D000539:Alveolar Process / Q000166:cytology / Q000201:enzymology; D020029:Base Pairing / Q000235:genetics; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D025021:Cementogenesis / Q000502:physiology; D003429:Cross Reactions / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D003739:Dental Cementum / Q000201:enzymology*; D005091:Exons / Q000235:genetics; D005347:Fibroblasts / Q000201:enzymology; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000166:cytology / Q000201:enzymology; D006801:Humans; D007438:Introns / Q000235:genetics; D009808:Odontogenic Tumors / Q000201:enzymology; D010513:Periodontal Ligament / Q000166:cytology / Q000201:enzymology; D020033:Protein Isoforms / Q000235:genetics; D017027:Protein Tyrosine Phosphatases / Q000302:isolation & purification*; D022821:RNA Splice Sites / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins; D020539:Sequence Analysis, Protein / Q000379:methods
chemical_list: D018076:DNA, Complementary; D020033:Protein Isoforms; D022821:RNA Splice Sites; D011994:Recombinant Proteins; C404489:HACD1 protein, human; D017027:Protein Tyrosine Phosphatases