Abstract

TAGLN is an actin-binding protein family that comprises three isoforms with theorized roles in smooth muscle differentiation, tumour development, lymphocyte activation, and brain chemistry. However, their fundamental characteristics in regulation of the actin-based cytoskeleton are not fully understood. Here we show that TAGLN2 (including TAGLN1 and TAGLN3) extensively nucleates G-actin polymerization under low-salt conditions, where polymerization would be completely suppressed. The calponin homology domain and actin-binding loop are essential to mechanically connect two adjacent G-actins, thereby mediating multimeric interactions. However, TAGLN2 blocked the Arp2/3 complex binding to actin filaments under physiological salt conditions, thereby inhibiting branched actin nucleation. In HeLa and T cells, TAGLN2 enhanced filopodium-like membrane protrusion. Collectively, the dual functional nature of TAGLN2—G-actin polymerization and Arp2/3 complex inhibition—may account for the mechanisms of filopodia development at the edge of Arp2/3-rich lamellipodia in various cell types.

Details

Title
TAGLN2 polymerizes G-actin in a low ionic state but blocks Arp2/3-nucleated actin branching in physiological conditions
Author
Kim, Hye-Ran 1 ; Min-Sung, Kwon 2 ; Lee, Sangmin 3 ; YeVin Mun 1 ; Lee, Kyung-Sik 1 ; Chang-Hyun, Kim 1 ; Bo-Ra Na 1 ; Bit Na Rae Kim 4 ; Piragyte, Indre 1 ; Hyun-Su, Lee 1 ; Youngsoo Jun 4 ; Mi Sun Jin 4 ; Young-Min, Hyun 5 ; Jung, Hyun Suk 3 ; Ji Young Mun 6 ; Chang-Duk, Jun 1 

 School of Life Sciences, GIST, Gwangju, Korea; Immune Synapse and Cell Therapy Research Center, GIST, Gwangju, Korea 
 School of Life Sciences, GIST, Gwangju, Korea; World Institute of Kimchi, Gwangju, Korea 
 Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si, Gangwon-do, Korea 
 School of Life Sciences, GIST, Gwangju, Korea 
 Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea 
 Department of Biomedical Laboratory Science, College of Health Science, Eulji University, Seongnam-si, Gyeonggi-do, Korea; Department of Structure and Function of Neural Network, Korea Brain Research Institute, Dong-gu, Daegu, Korea 
Pages
1-15
Publication year
2018
Publication date
Apr 2018
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2021297509
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.