A Combined Zinc/Cadmium Sensor and Zinc/Cadmium Export Regulator in a Heavy Metal Pump

• DOI: 10.1074/jbc.m110.111260
• Publication Date: 2010-07-23T00:23:27Z
• Authors: Lone Bækgaard; Maria D. Mikkelsen; Danny M. Sørensen; Josefine N. Hegelund; Daniel P. Persson; Rebecca F. Mills; Zhang Yang; Søren Husted; Jens Peter Andersen; Morten J. Buch-Pe...; Jan K. Schjoerring; Lorraine E. Williams; Michael G. Palmgren
• Keywords: C-terminus

Heavy metal pumps (P1B-ATPases) are important for cellular heavy homeostasis. AtHMA4, an Arabidopsis thaliana pump of importance plant Zn2+ nutrition, has extended C-terminal domain containing 13 cysteine pairs and a terminal stretch 11 histidines. Using novel size-exclusion chromatography, inductively coupled plasma mass spectrometry approach we report that the AtHMA4 is high affinity Cd2+ chelator with capacity to bind 10 ions per C terminus. When expressed in Zn2+-sensitive zrc1 cot1 yeast strain, sequential removal histidine confers gradual increase tolerance lowered content transformed cells. We conclude serves dual role as (sensor) regulator efficiency export. The identification post-translational handle on transport opens new perspectives regulation nutrition eukaryotes.