A transcript encoding a nucleic acid-binding protein specifically expressed in maize seeds.

Area of Science:

• Plant molecular biology
• Gene regulation
• Protein biochemistry

Background:

• Seed development involves complex gene expression regulation.
• Molecular chaperones play critical roles in protein folding and cellular processes.
• Novel proteins with potential regulatory functions are frequently discovered in plant endosperm.

Purpose of the Study:

• To characterize a novel seed-specific protein, MEM1, from maize.
• To investigate the DNA/RNA binding and dimerization properties of MEM1.
• To explore the potential function of MEM1 in maize endosperm development.

Main Methods:

• cDNA cloning and sequencing to identify the MEM1 gene.
• Yeast one-hybrid system to assess transcriptional activation.
• In vitro nucleic acid binding assays.
• Recombinant protein expression and purification.
• Native PAGE and co-immunoprecipitation for dimerization studies.
• Subcellular and size fractionation.

Main Results:

• A cDNA clone encoding MEM1, a novel protein family member related to DnaJ chaperones, was obtained.
• MEM1 binds to the endosperm motif and activates transcription in yeast.
• Recombinant MEM1 exhibits in vitro nucleic acid binding, with a preference for RNA.
• MEM1 forms homodimers, dependent on a C-terminal domain.
• MEM1 is expressed in mid- to late-term endosperm cells and localized to the cytosol.

Conclusions:

• MEM1 represents a novel class of plant proteins with potential roles in gene regulation.
• Its nucleic acid binding and dimerization capabilities suggest involvement in RNA metabolism or protein complex formation.
• MEM1 may contribute to endosperm and protein body development in maize.