CUP1-2 Antibody

Antibody Overview

The CUP1-2 antibody (e.g., PACO63579) is a polyclonal antibody developed to study the CUP1 metallothionein, a copper-binding protein essential for cellular copper regulation. It is primarily used to detect CUP1 in cytosol and mitochondrial fractions under varying copper conditions .

Biological Context of CUP1

CUP1 is a metallothionein with two paralogs (CUP1-1 and CUP1-2) in S. cerevisiae, arising from segmental duplication . These proteins:

• Bind 8 copper ions cooperatively in their holo-form .

• Localize to both cytosol and mitochondrial intermembrane space (IMS) .

• Protect cells from copper toxicity by sequestering excess copper .

• Influence low-molecular-mass (LMM) copper complexes in mitochondria .

Research Applications

The CUP1-2 antibody facilitates studies on:

Copper Homeostasis Mechanisms

• Detection of CUP1 in cytosol and mitochondria under copper-replete conditions .

• Analysis of copper-dependent CUP1 expression using chromatin immunoprecipitation (ChIP) .

Stress Response Studies

• Monitoring CUP1’s role in nitrosative stress tolerance:

  • Deletion of CUP1 increases sensitivity to nitric oxide (NO) .

  • Overexpression enhances NO scavenging capacity .

Mitochondrial Copper Dynamics

• CUP1 in the IMS may regulate LMM copper pools, preventing oxidative damage .

Localization Studies

• Fluorescence microscopy confirmed mitochondrial uptake of CUP1-GFP fusion proteins .

• CUP1 in IMS was validated via mitoplasting experiments .

Genetic Interactions

• CUP1 deletion strains show altered LMM copper complexes and increased sensitivity to metals .

• Overexpression reduces intracellular free copper, impacting copper-dependent enzymes like Sod1p .

Technical Considerations

• Cross-Reactivity: The antibody may recognize both CUP1-1 and CUP1-2 due to high sequence similarity .

• Applications: Optimized for ELISA and Western blot under non-denaturing conditions .

• Limitations: Requires validation in strains with CUP1 paralog-specific deletions to avoid cross-reactivity .

Implications for Disease Research

• Insights into yeast copper regulation inform studies on human disorders like Wilson’s and Menkes diseases .

• CUP1’s role in nitrosative stress highlights potential therapeutic targets for oxidative damage .