cDNA sequence, genomic structure, and expression of the mouse dematin gene (Epb4.9)

• Published in: Mammalian genome Vol. 10; no. 10; pp. 1026 - 1029
• Main Authors: Azim, A C, Kim, A C, Lutchman, M, Andrabi, S, Peters, L L, Chishti, A H
• Format: Journal Article
• Language: English
• Published: United States Springer Nature B.V 01.10.1999
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Blood Proteins - chemistry; Blood Proteins - genetics; Cloning, Molecular; Cytoskeletal Proteins; Erythrocytes - chemistry; Exons; Gene Expression - genetics; Introns; Membrane Proteins - chemistry; Membrane Proteins - genetics; Mice; Molecular Sequence Data; Phosphoproteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Sequence Homology, Amino Acid
• ISSN: 0938-8990; 1432-1777
• DOI: 10.1007/s003359901153

Dematin (protein 4.9 region) is an actin-bundling phosphoprotein of the erythroid membrane cytoskeleton (Rana et al. 1993; Azim et al. 1995). Although much is known about the functions of the core group of erythroid membrane proteins, such as spectrin, ankyrin, band 3, and protein 4.1, relatively little is known concerning the physiological role of dematin in vivo. In vitro, dematin's actin-bundling activity is abolished upon phosphorylation by the cAMP-dependent protein kinase (Chishti et al. 1988). The significance of dematin's actin-bundling activity in erythrocytes is unknown. Actin bundles are not present in mature erythrocytes but do exist in early erythroblasts where dematin's catalytic activity may be functionally significant (Koury et al. 1989). The primary sequence of dematin consists of an aminoterminal core domain of unknown function and a carboxy-terminal domain homologous to the "headpiece" domain of villin, an actin-binding protein of the brush border cytoskeleton (Rana et al. 1993; Arpin et al. 1988). This domain has since been identified in several other proteins including limatin (abLIM), supervillin, and advillin (Roof et al. 1997; Pestonjamasp et al. 1997; Marks et al. 1998). Transfection and mutagenesis studies of villin cDNAs revealed the headpiece domain to be crucial in microvilli morphogenesis (Friederich et al. 1992). While the normal development of microvilli in villin knockout mice seems to contradict the importance of villin, this observation suggests that dematin and/or other headpiece-containing proteins may compensate for villin function in the absorptive epithelia (Pinson et al. 1998). Here we report the cDNA sequence, genomic organization, and the mRNA expression of mouse dematin in fetal and adult tissues. The primary characterization of mouse erythroid dematin is the critical first step in generating knockout mice to study dematin function.