The actin cytoskeleton is one of the targets of the pH gradient in tip-growing cells, but how cytosolic pH regulates the actin cytoskeleton remains largely unknown. We here demonstrate that Arabidopsis ADF7 and ADF10 function optimally at different pH levels when disassembling actin filaments. This differential pH sensitivity allows ADF7 and ADF10 to respond to the cytosolic pH gradient to regulate actin dynamics in pollen tubes. ADF7 is an unusual actin-depolymerizing factor with a low optimum pH in in vitro actin depolymerization assays. ADF7 plays a dominant role in promoting actin turnover at the pollen tube apex. ADF10 has a typically high optimum pH in in vitro assays and plays a dominant role in regulating the turnover and organization of subapical actin filaments. Thus, functional specification and cooperation of ADF isovariants with different pH sensitivities enable the coordination of the actin cytoskeleton with the cytosolic pH gradient to support pollen tube growth.
Differential sensitivity of ADF isovariants to a pH gradient promotes pollen tube growth
Disclosures: The authors declare no competing interests exist.
- Award Id(s): 32270338,31970180
Juan Wang, Jiangfeng Shen, Yanan Xu, Yuxiang Jiang, Xiaolu Qu, Wanying Zhao, Yingjie Wang, Shanjin Huang; Differential sensitivity of ADF isovariants to a pH gradient promotes pollen tube growth. J Cell Biol 6 November 2023; 222 (11): e202206074. doi: https://doi.org/10.1083/jcb.202206074
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