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The Nicotiana tabacum plasma membrane aquaporin NtAQP1 is mercury‐insensitive and permeable for glycerol
Author(s) -
Biela Alexander,
Grote Karsten,
Otto Beate,
Hoth Stefan,
Hedrich Rainer,
Kaldenhoff Ralf
Publication year - 1999
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1999.00474.x
Subject(s) - nicotiana tabacum , aquaporin , xenopus , chemistry , water transport , glycerol , membrane , biochemistry , botany , biology , microbiology and biotechnology , biophysics , gene , water flow , environmental engineering , engineering
Summary A new aquaporin from Nicotiana tabacum (cv. Samsun) was characterized. It shares sequence homology to the Arabidopsis thaliana PIP1 protein family. By two‐phase partitioning and immunoblot analysis, plasma membrane localization could be demonstrated. The corresponding mRNA is highly abundant in roots and flowers, while it is rarely expressed in leaves and stems. Functional expression in Xenopus oocytes revealed that NtAQP1 can mediate glycerol transport in addition to water flow. However, NtAQP1 is impermeable for Na+, K+and Cl–ions. The water permeability and selectivity could not be modulated by addition of mercurials or the activity of cAMP‐dependent protein kinases.