FTSHI5 Antibody

Introduction to FTSHi5 Antibody

The FTSHi5 antibody targets the FTSHi5 protein, a member of the FtsH-inactive (FtsHi) family within chloroplasts. Unlike canonical FtsH proteases, FTSHi5 lacks proteolytic activity due to the absence of a zinc-binding motif but is essential for chloroplast biogenesis and protein import . This antibody enables detection and functional analysis of FTSHi5 in plant tissues, particularly under varying environmental conditions.

Target Protein Characteristics

FTSHi5 is a chloroplast-localized protein with the following features:

Research Applications

The FTSHi5 antibody has been employed in:

• Immunoblotting: Detecting FTSHi5 in chloroplast membrane fractions .

• Protein Complex Analysis: Identifying interactions within the 2-MDa TIC-TOC supercomplex (e.g., with FtsHi1, FtsHi2, Ycf2) .

• Functional Studies: Investigating temperature-dependent chloroplast defects in ftsHi5 mutants .

• Subcellular Localization: Confirming intermembrane space localization via protease protection assays .

Role in Chloroplast Development

• FTSHi5 is required for thylakoid membrane formation, particularly at low temperatures (16–18°C). Mutants exhibit pale-green leaves and disrupted chloroplast ultrastructure .

• Quantitative proteomics revealed reduced accumulation of photosynthetic proteins (e.g., D1, PsbO) in ftsHi5 mutants at 16°C .

Thermo-Sensitive Phenotype

• The tsl2 (thermo-sensitive leaf color 2) mutant, allelic to ftsHi5, shows rescued chloroplast development at 29°C but severe defects at 16°C .

• Complementation with wild-type FTSHi5 restores chlorophyll content and thylakoid organization .

Association with Protein Import Machinery

• FTSHi5 forms a heteromeric complex with FtsHi1, FtsHi2, FtsHi4, FtsH12, Ycf2, and pdNAD-MDH at the inner chloroplast envelope, driving preprotein translocation .

• This complex exhibits ATPase activity, critical for maintaining protein import efficiency .

Associated Protein Complexes

FTSHi5 interacts with multiple proteins critical for chloroplast function:

Future Directions

Current research gaps include:

• Structural resolution of the FTSHi5-containing complex via cryo-EM.

• Mechanistic studies on ATP hydrolysis-driven protein import.

• Exploring FTSHi5’s role in crop resilience to cold stress .