In vitro characterization of native mammalian smooth-muscle protein synaptopodin 2. Issue 4 (1st September 2008)

• Record Type: Journal Article
• Authors: Schroeter, Mechthild M.; Beall, Brent; Heid, Hans W.; Chalovich, Joseph M.
• Is Part Of: Bioscience reports. Volume 28:Issue 4(2008)
• Page Start: 195
• Page End: 203
• Publication Date: 2008-09-01
• Subjects: actin-binding protein -- actin polymerization -- Ca2+–calmodulin regulation -- fesselin -- myopodin -- synaptopodin 2; Molecular biology -- Periodicals; Cytology -- Periodicals; 572.8
• DOI: 10.1042/BSR20080079
• Languages: English
• ISSNs: 0144-8463

Abstract

Abstract : An analysis of the primary structure of the actin-binding protein fesselin revealed it to be the avian homologue of mammalian synaptopodin 2 [Schroeter, Beall, Heid, and Chalovich (2008) Biochem. Biophys. Res. Commun. 371, 582–586]. We isolated two synaptopodin 2 isoforms from rabbit stomach that corresponded to known types of human synaptopodin 2. The purification scheme used was that developed for avian fesselin. These synaptopodin 2 forms shared several key functions with fesselin. Both avian fesselin and mammalian synaptopodin 2 bound to Ca 2+ –calmodulin, α-actinin and smooth-muscle myosin. In addition, both proteins stimulated the polymerization of actin in a Ca 2+ –calmodulin-dependent manner. Synaptopodin 2 has never before been shown to polymerize actin in the absence of α-actinin, to polymerize actin in a Ca 2+ –calmodulin-dependent manner, or to bind to Ca 2+ –calmodulin or myosin. These properties are consistent with the proposed function of synaptopodin 2 in organizing the cytoskeleton.