Identification of the First Eukaryotic Molybdenum Transporter

Molybdenum is one of the least abundant elements in many organisms yet it performs a number of important roles as a metal cofactor. Cofactors are enzyme-bound non-protein compounds, necessary for the enzyme’s catalytic activity. As a cofactor, molybdenum is required for the activity of essential enzymes that perform functions like nitrate assimilation (nitrate reductase), plant hormone synthesis and purine (major component of DNA and RNA) metabolism. Adequate levels of molybdenum minimize the presence of toxic nitrites and nitrates in plant tissues.

A group of Spanish scientist has identified the first molybdenum transporter (molecule required for the entry/exit of molecules within cell membranes) in eukaryotes. The researchers identified the transporter from the model green alga Chlamydomonas. When the gene coding for the transporter, MOT1, was silenced through RNAi, molybdate transport and activity of the nitrate reductase enzyme was inhibited. The discovery made by the researchers represents an important step in the understanding of molybdate transport in both plant and animal cells.

Read the abstract at http://www.pnas.org/cgi/content/abstract/0704646104v1 or the full paper at http://www.pnas.org/cgi/reprint/0704646104v1