A survey of barley pip aquaporin ionic conductance reveals ca2+-sensitive hvpip2;8 na+ and k+ conductance

Sen Thi Huong Tran, Shahin Imran, Tomoaki Horie, Jiaen Qiu, Samantha McGaughey, Caitlin S. Byrt, Stephen D. Tyerman, Maki Katsuhara

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


Some plasma membrane intrinsic protein (PIP) aquaporins can facilitate ion transport. Here we report that one of the 12 barley PIPs (PIP1 and PIP2) tested, HvPIP2;8, facilitated cation transport when expressed in Xenopus laevis oocytes. HvPIP2;8-associated ion currents were detected with Na+ and K+, but not Cs+, Rb+, or Li+, and was inhibited by Ba2+, Ca2+, and Cd2+ and to a lesser extent Mg2+, which also interacted with Ca2+. Currents were reduced in the presence of K+, Cs+, Rb+, or Li+ relative to Na+ alone. Five HvPIP1 isoforms co-expressed with HvPIP2;8 inhibited the ion conductance relative to HvPIP2;8 alone but HvPIP1;3 and HvPIP1;4 with HvPIP2;8 maintained the ion conductance at a lower level. HvPIP2;8 water permeability was similar to that of a C-terminal phosphorylation mimic mutant HvPIP2;8 S285D, but HvPIP2;8 S285D showed a negative linear correlation between water permeability and ion conductance that was modified by a kinase inhibitor treatment. HvPIP2;8 transcript abundance increased in barley shoot tissues following salt treatments in a salt-tolerant cultivar Haruna-Nijo, but not in salt-sensitive I743. There is potential for HvPIP2;8 to be involved in barley salt-stress responses, and HvPIP2;8 could facilitate both water and Na+/K+ transport activity, depending on the phosphorylation status.

Original languageEnglish
Article number7135
Pages (from-to)1-20
Number of pages20
JournalInternational journal of molecular sciences
Issue number19
Publication statusPublished - Oct 1 2020


  • Aquaporins
  • Barley
  • Ion transport
  • Oocytes
  • Plasma membrane intrinsic proteins (PIPs)

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry


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