High impact information on CAX3

• We show that these mutants exhibit a 50% reduction in tonoplast Ca(2+)/H(+) antiport activity, a 40% reduction in tonoplast V-type H(+)-translocating ATPase activity, a 36% increase in tonoplast Ca(2+)-ATPase activity, and increased expression of the putative vacuolar Ca(2+)/H(+) antiporters CAX3 and CAX4 [1].
• Chimeric CAX3 constructs containing the N terminus of CAX1 were activated by CXIP1 [2].
• Functional association of Arabidopsis CAX1 and CAX3 is required for normal growth and ion homeostasis [3].
• When expressed in yeast, CAX4, like CAX3, failed to suppress the Ca(2+) sensitivity of yeast strains deficient in vacuolar Ca(2+) transport [4].
• Additions of either the CAX3 or VCAX1 regulatory regions to the N terminus of an N-terminal truncated CAX1 failed to inhibit CAX1 activity [5].

Biological context of CAX3

• When fused to N-terminal truncated CAX1, both the CAX3 and VCAX1 regulatory regions could only auto-inhibit CAX1 after mutagenesis of specific amino acids within this NRR region [5].

Anatomical context of CAX3

• An Arabidopsis thaliana homolog of CAX1, CAX3, is 77% identical (93% similar) and, when expressed in yeast, localized to the vacuole but did not suppress yeast mutants defective in vacuolar Ca(2+) transport [6].

Associations of CAX3 with chemical compounds

• Site-directed mutagenesis of the leucine in the CAX3 Cad demonstrated that no amino acid change tested could confer more activity than CAX3-I [7].

Regulatory relationships of CAX3

• Chimeric constructs and site-directed mutagenesis showed that CAX3 could suppress yeast vacuolar Ca(2+) transport mutants if a nine-amino acid region of CAX1 was inserted into CAX3 (CAX3-9) [6].

Other interactions of CAX3

• We show that CAX1 is predominately expressed in leaves, while CAX3 is highly expressed in roots [3].

References