The contractile proteins of dictyostelium discoideum

✍ Scribed by Spudich, James A. ;Clarke, Margaret

• Publisher: Wiley (John Wiley & Sons)
• Year: 1974
• Tongue: English
• Weight: 738 KB
• Volume: 2
• Category: Article
• ISSN: 0091-7419
• DOI: 10.1002/jss.400020209

✦ Synopsis

Abstract

We have purified actin and my osin‐like proteins from amoebae of Dictyostelium discoideum. These proteins are very similar in their physical and enzymatic properties to muscle actin and myosin. Most importantly, they form thin and thick filaments, respectively, and Dictyostelium actin activates Dictyostelium myosin ATPase activity. Actin from these amoebae appears to be identical in size to muscle actin. The Dictyostelium myosin consists of two heavy chains of about 210,000 daltons and two classes of light chains, about 18,000 and 16,000 daltons. The heavy chains are slightly larger than those of muscle myosin. Biochemical and structural studies of membrane association of the contractile complex suggests that some of the amoeba actin is membrane‐bound and acts as an attachment point for myosin and other actin filaments.