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Cancer Cell death Cell cycle Cytoskeleton Exo/endocytosis Differentiation Division Organelles Signalling Stem cells Trafficking
Cell Biology International (2009) 33, 816–829 (Printed in Great Britain)
Tissue-specific expression of dentin sialophosphoprotein (DSPP) and its polymorphisms in mouse tissues
Guohua Yuanac, Yinghua Wanga, Jelica Gluhak‑Heinrichb, Guobin Yanga, Lei Chena, Tong Lia, Li‑An Wua, Zhi Chend, Mary MacDougalle* and Shuo Chena**
aDepartment of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
bDepartment of Orthopedics, Dental School, The University of Texas Health Science Center at San Antonio, TX, USA
cKey Laboratory of Oral Biomedical Engineering Ministry of Education, Wuhan University School and Hospital of Stomatology, Wuhan, China
dDepartment of Cariology and Endodontics, Wuhan University School and Hospital of Stomatology, Wuhan, China
eDepartment of Oral/Maxillofacial Surgery, University of Alabama, School of Dentistry, 1919 7th Avenue South, SDB 702, Birmingham, AL 35294-0007, USA


Abstract

Dentin sialophosphoprotein (DSPP) consists of dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). DSPP is highly expressed in mineralized tissues. However, recent studies have shown that DSPP is also expressed in several active metabolic ductal epithelial tissues and exists in a variety of sequences. We have investigated DSPP expression in various mouse tissues using RT-PCR, in situ hybridization and immunohistochemical analyses. To identify DSPP gene polymorphisms, we screened a mouse tooth cDNA library as well as isolated and characterized DSPP variations. Our results show that DSPP is predominantly expressed in teeth and moderately in bone tissues. We also have characterized a full-length DSPP cDNA clone with an open-reading frame of 940 codons and this polyadenylation signal. Compared to previously reported mouse DSPP cDNAs, 13 sequence variations were identified, including 8 non-synonymous single nucleotide polymorphisms and an in-frame indel (8 amino acids) at DPP domain of the mouse DSPP. These 8 amino acids are rich in aspartic acid and serine residues. Northern blot assay showed a prominent band at 4.4kb. RT-PCR demonstrated that this mouse DSPP gene was dominantly expressed in teeth. The predicted secondary structure of DPP domain of this DSPP showed differences from the previously published mouse DPPs, implying that they play different roles during tooth development and formation.


Key words: Dentin sialophosphoprotein (DSPP), Dentin sialoprotein (DSP), Dentin phosphoprotein (DPP), Polymorphism, Dentinogenesis.

*Corresponding author. Tel.: +1 205 996 5122; fax: +1 205 996 5104.

**Corresponding author. Tel.: +1 210 567 3511; fax: +1 210 567 6603.


Received 20 December 2008/11 March 2009; accepted 7 May 2009

doi:10.1016/j.cellbi.2009.05.001


ISSN Print: 1065-6995
ISSN Electronic: 1095-8355
Published by Portland Press Limited on behalf of the International Federation for Cell Biology (IFCB)