2. Academic Validation
  3. Structures and mechanisms of the Arabidopsis cytokinin transporter AZG1

Structures and mechanisms of the Arabidopsis cytokinin transporter AZG1

  • Nat Plants. 2024 Jan;10(1):180-191. doi: 10.1038/s41477-023-01590-y.
Lingyi Xu # 1 2,  Wei Jia # 3 4,  Xin Tao # 5,  Fan Ye 6 7,  Yan Zhang 6 7,  Zhong Jie Ding 8,  Shao Jian Zheng 8,  Shuai Qiao 9,  Nannan Su 9,  Yu Zhang 10,  Shan Wu 11,  Jiangtao Guo 12 13 14 15 16 17
Affiliations

Affiliations

  • 1 Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. [email protected].
  • 2 Nanhu Brain-computer Interface Institute, Hangzhou, China. [email protected].
  • 3 National Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China.
  • 4 Calibra Lab at DIAN Diagnostics, Key Laboratory of Digital Technology in Medical Diagnostics of Zhejiang Provinces, Hangzhou, Zhejiang, China.
  • 5 State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei, China.
  • 6 Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
  • 7 Nanhu Brain-computer Interface Institute, Hangzhou, China.
  • 8 State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China.
  • 9 International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China.
  • 10 National Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang, China. [email protected].
  • 11 State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei, China. [email protected].
  • 12 Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. [email protected].
  • 13 Nanhu Brain-computer Interface Institute, Hangzhou, China. [email protected].
  • 14 NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China. [email protected].
  • 15 Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. [email protected].
  • 16 Cancer Center, Zhejiang University, Hangzhou, Zhejiang, China. [email protected].
  • 17 Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China. [email protected].
  • # Contributed equally.
PMID: 38172575 DOI: 10.1038/s41477-023-01590-y
Abstract

Cytokinins are essential for plant growth and development, and their tissue distributions are regulated by transmembrane transport. Recent studies have revealed that members of the 'Aza-Guanine Resistant' (AZG) protein family from Arabidopsis thaliana can mediate Cytokinin uptake in roots. Here we present 2.7 to 3.3 Å cryo-electron microscopy structures of Arabidopsis AZG1 in the apo state and in complex with its substrates trans-zeatin (tZ), 6-benzyleaminopurine (6-BAP) or kinetin. AZG1 forms a homodimer and each subunit shares a similar topology and domain arrangement with the proteins of the nucleobase/ascorbate transporter (NAT) family. These structures, along with functional analyses, reveal the molecular basis for Cytokinin recognition. Comparison of the AZG1 structures determined in inward-facing conformations and predicted by AlphaFold2 in the occluded conformation allowed us to propose that AZG1 may carry cytokinins across the membrane through an elevator mechanism.

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