At FH16, an Arabidopsis Type II Formin, Binds and Bundles both Microflaments and Microtubules, and Preferentially Binds to Microtubules  

作　　者：Jiaojiao Wang Yi Zhang Jing Wu Lei Meng Haiyun Ren 

机构地区：[1]The Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University

出　　处：《Journal of Integrative Plant Biology》2013年第11期1002-1015,共14页植物学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (31130005);the National Basic Research Program of China (2013CB126902) to H. R.

摘　　要：Formins are well-known regulators that participate in the organization of the actin cytoskeleton in organisms. The Arabidopsis thaliana L. genome encodes 21 formins, which can be divided into two distinct subfamilies. However, type II formins have to date been less well characterized. Here, we cloned a type II formin, AtFH16, and characterized its biochemical activities on actin and microtubule dynamics. The results show that the FH1 FH2 structure of AtFH16 cannot nucleate actin polymerization efficiently, but can bind and bundle microfilaments. AtFH16 FHIFH2 is also able to bind and bundle microtubules, and preferentially binds microtubules over microfilaments in vitro, in addition, AtFH16 FHIFH2 co-localizes with microtubules in onion epidermal cells, indicating a higher binding affinity of AtFH16 FHIFH2 for microtubules rather than microfilaments in vivo. In conclusion, AtFH16 is able to interact with both microfilaments and microtubules, suggesting that AtFH16 probably functions as a bifunctional protein, and may thus participate in plant cellular processes.Formins are well-known regulators that participate in the organization of the actin cytoskeleton in organisms. The Arabidopsis thaliana L. genome encodes 21 formins, which can be divided into two distinct subfamilies. However, type II formins have to date been less well characterized. Here, we cloned a type II formin, AtFH16, and characterized its biochemical activities on actin and microtubule dynamics. The results show that the FH1 FH2 structure of AtFH16 cannot nucleate actin polymerization efficiently, but can bind and bundle microfilaments. AtFH16 FHIFH2 is also able to bind and bundle microtubules, and preferentially binds microtubules over microfilaments in vitro, in addition, AtFH16 FHIFH2 co-localizes with microtubules in onion epidermal cells, indicating a higher binding affinity of AtFH16 FHIFH2 for microtubules rather than microfilaments in vivo. In conclusion, AtFH16 is able to interact with both microfilaments and microtubules, suggesting that AtFH16 probably functions as a bifunctional protein, and may thus participate in plant cellular processes.

关 键 词：Actin filament ARABIDOPSIS cytoskeleton FORMIN microtubule. 

分 类 号：Q946[生物学—植物学]