z-logo
Premium
Oryza sativa actin‐interacting protein 1 is required for rice growth by promoting actin turnover
Author(s) -
Shi Meng,
Xie Yurong,
Zheng Yiyan,
Wang Junmin,
Su Yi,
Yang Qiuying,
Huang Shanjin
Publication year - 2013
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12065
Subject(s) - cofilin , actin remodeling , mdia1 , actin remodeling of neurons , profilin , microbiology and biotechnology , actin binding protein , actin , depolymerization , actin cytoskeleton , biology , chemistry , cytoskeleton , biochemistry , cell , organic chemistry
Summary Rapid actin turnover is essential for numerous actin‐based processes. However, how it is precisely regulated remains poorly understood. Actin‐interacting protein 1 ( AIP 1) has been shown to be an important factor by acting coordinately with actin‐depolymerizing factor ( ADF )/cofilin in promoting actin depolymerization, the rate‐limiting factor in actin turnover. However, the molecular mechanism by which AIP 1 promotes actin turnover remains largely unknown in plants. Here, we provide a demonstration that AIP 1 promotes actin turnover, which is required for optimal growth of rice plants. Specific down‐regulation of Os AIP 1 increased the level of filamentous actin and reduced actin turnover, whereas over‐expression of Os AIP 1 induced fragmentation and depolymerization of actin filaments and enhanced actin turnover. In vitro biochemical characterization showed that, although Os AIP 1 alone does not affect actin dynamics, it enhances ADF ‐mediated actin depolymerization. It also caps the filament barbed end in the presence of ADF , but the capping activity is not required for their coordinated action. Real‐time visualization of single filament dynamics showed that Os AIP 1 enhanced ADF ‐mediated severing and dissociation of pointed end subunits. Consistent with this, the filament severing frequency and subunit off‐rate were enhanced in OsAIP1 over‐expressors but decreased in RNA i protoplasts. Importantly, Os AIP 1 acts coordinately with ADF and profilin to induce massive net actin depolymerization, indicating that AIP 1 plays a major role in the turnover of actin, which is required to optimize F‐actin levels in plants.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here