Score: 7.00 | Title: Rice two-pore K+ channels are expressed in different types of vacuoles .
| Author: Isayenkov S Isner JC Maathuis FJ | Journal: Plant Cell Citation: V : 23 P : 756-68 Year: 2011 Type: MEDLINE | Literature: oryza Field: abstract Doc ID: pub21224427 Accession (PMID): 21224427 | Abstract: Potassium ( K+ ) is a major nutrient for plant growth and development .
Vacuolar K+ ion channels of the two-pore K+ ( TPK ) family play an important role in maintaining K+ homeostasis .
Several TPK channels were previously shown to be expressed in the lytic vacuole ( LV ) tonoplast Plants also contain smaller protein storage vacuoles ( PSVs ) that contain membrane transporters .
However , the mechanisms that define how membrane proteins reach different vacuolar destinations are largely unknown .
The Oryza sativa genome encodes two TPK isoforms ( TPKa and TPKb ) that have very similar sequences and are ubiquitously expressed .
The electrophysiological properties of both TPKs were comparable , showing inward rectification and voltage independence .
In spite of high levels of similarity in sequence and transport properties , the cellular localization of TPKa and TPKb channels was different , with TPKa localization predominantly at the large LV and TPKb primarily in smaller PSV-type compartments .
Trafficking of TPKa was sensitive to brefeldin A , while that of TPKb was not .
The use of TPKa : TPKb chimeras showed that C-terminal domains are crucial for the differential targeting of TPKa and TPKb .
Site-directed mutagenesis of C-terminal residues that were different between TPKa and TPKb identified three amino acids that are important in determining ultimate vacuolar destination .
| Matching Sentences: [ Sen. 7, subscore: 2.00 ]: Several TPK channels were previously shown to be expressed in the lytic vacuole ( LV ) tonoplast Plants also contain smaller protein storage vacuoles ( PSVs ) that contain membrane transporters . However , the mechanisms that define how membrane proteins reach different vacuolar destinations are largely unknown . The Oryza sativa genome encodes two TPK isoforms ( TPKa and TPKb ) that have very similar sequences and are ubiquitously expressed . The electrophysiological properties of both TPKs were comparable , showing inward rectification and voltage independence . In spite of high levels of similarity in sequence and transport properties , the cellular localization of TPKa and TPKb channels was different , with TPKa localization predominantly at the large LV and TPKb primarily in smaller PSV-type compartments . Trafficking of TPKa was sensitive to brefeldin A , while that of TPKb was not . The use of TPKa : TPKb chimeras showed that C-terminal domains are crucial for the differential targeting of TPKa and TPKb . Site-directed mutagenesis of C-terminal residues that were different between TPKa and TPKb identified three amino acids that are important in determining ultimate vacuolar destination . [ Sen. 9, subscore: 2.00 ]: The Oryza sativa genome encodes two TPK isoforms ( TPKa and TPKb ) that have very similar sequences and are ubiquitously expressed . The electrophysiological properties of both TPKs were comparable , showing inward rectification and voltage independence . In spite of high levels of similarity in sequence and transport properties , the cellular localization of TPKa and TPKb channels was different , with TPKa localization predominantly at the large LV and TPKb primarily in smaller PSV-type compartments . Trafficking of TPKa was sensitive to brefeldin A , while that of TPKb was not . The use of TPKa : TPKb chimeras showed that C-terminal domains are crucial for the differential targeting of TPKa and TPKb . Site-directed mutagenesis of C-terminal residues that were different between TPKa and TPKb identified three amino acids that are important in determining ultimate vacuolar destination . [ Sen. 5, subscore: 1.00 ]: Potassium ( K+ ) is a major nutrient for plant growth and development . Vacuolar K+ ion channels of the two-pore K+ ( TPK ) family play an important role in maintaining K+ homeostasis . Several TPK channels were previously shown to be expressed in the lytic vacuole ( LV ) tonoplast Plants also contain smaller protein storage vacuoles ( PSVs ) that contain membrane transporters . However , the mechanisms that define how membrane proteins reach different vacuolar destinations are largely unknown . The Oryza sativa genome encodes two TPK isoforms ( TPKa and TPKb ) that have very similar sequences and are ubiquitously expressed . The electrophysiological properties of both TPKs were comparable , showing inward rectification and voltage independence . In spite of high levels of similarity in sequence and transport properties , the cellular localization of TPKa and TPKb channels was different , with TPKa localization predominantly at the large LV and TPKb primarily in smaller PSV-type compartments . Trafficking of TPKa was sensitive to brefeldin A , while that of TPKb was not . The use of TPKa : TPKb chimeras showed that C-terminal domains are crucial for the differential targeting of TPKa and TPKb . [ Sen. 8, subscore: 1.00 ]: However , the mechanisms that define how membrane proteins reach different vacuolar destinations are largely unknown . The Oryza sativa genome encodes two TPK isoforms ( TPKa and TPKb ) that have very similar sequences and are ubiquitously expressed . The electrophysiological properties of both TPKs were comparable , showing inward rectification and voltage independence . In spite of high levels of similarity in sequence and transport properties , the cellular localization of TPKa and TPKb channels was different , with TPKa localization predominantly at the large LV and TPKb primarily in smaller PSV-type compartments . Trafficking of TPKa was sensitive to brefeldin A , while that of TPKb was not . The use of TPKa : TPKb chimeras showed that C-terminal domains are crucial for the differential targeting of TPKa and TPKb . Site-directed mutagenesis of C-terminal residues that were different between TPKa and TPKb identified three amino acids that are important in determining ultimate vacuolar destination . [ Sen. 10, subscore: 1.00 ]: The electrophysiological properties of both TPKs were comparable , showing inward rectification and voltage independence . In spite of high levels of similarity in sequence and transport properties , the cellular localization of TPKa and TPKb channels was different , with TPKa localization predominantly at the large LV and TPKb primarily in smaller PSV-type compartments . Trafficking of TPKa was sensitive to brefeldin A , while that of TPKb was not . The use of TPKa : TPKb chimeras showed that C-terminal domains are crucial for the differential targeting of TPKa and TPKb . Site-directed mutagenesis of C-terminal residues that were different between TPKa and TPKb identified three amino acids that are important in determining ultimate vacuolar destination .
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