title: Extremely low polymerizability of a highly-divergent Chlamydomonas actin (NAP).
abstract: Novel actin-like protein (NAP) is a highly divergent actin expressed in Chlamydomonas. With its low sequence similarity, it is uncertain whether NAP can polymerize into filaments. Here I assessed it by ectopically expressing enhanced green fluorescent protein-tagged NAP (EGFP-NAP) in cultured cells. EGFP-NAP was excluded from stress fibres but partially co-localized with endogenous actin in the cell periphery. In fluorescence recovery after photobleaching experiment, turnover rate of EGFP-NAP was similar to the estimated diffusion rate of monomeric actin. Therefore, EGFP-NAP likely accumulates by diffusion. These findings suggest that NAP has extremely poor ability to polymerize.
authors.affiliation: Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Tokyo, Japan. minoura@bio.chuo-u.ac.jp
authors.forename: Takako
authors.initials: T
authors.lastname: Kato-Minoura
mesh_terms: D000199:Actins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002696:Chlamydomonas / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D058105:Polymerization; D011487:Protein Conformation
chemical_list: D000199:Actins; C117538:actin-like protein, NAP; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins