RECK isoforms have opposing effects on cell migration.

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Cell migration is crucial for development and disease, involving cytoskeletal changes and extracellular matrix remodeling.
• Mechanisms of cell motility are well-studied, but the role of alternative isoform expression remains largely unexplored.
• Reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) is a known inhibitor of cell migration.

Purpose of the Study:

• To investigate the impact of alternative RECK isoform expression on cell migration.
• To elucidate the molecular mechanisms by which RECK isoforms regulate cell motility.

Main Methods:

• Analysis of RECK isoform expression in proliferating and differentiated cells, TGF-β-treated fibroblasts, and tumor tissues.
• RNA interference (RNAi) to knockdown specific RECK isoforms.
• Cell migration assays using Matrigel.
• Co-immunoprecipitation to study protein-protein interactions.

Main Results:

• A shorter RECK isoform is upregulated in proliferating fibroblasts, TGF-β-treated fibroblasts, and tumors.
• Knockdown of the short RECK isoform decreases fibroblast migration.
• The short RECK isoform competes with matrix metalloprotease 9 (MMP9) for binding to the canonical RECK isoform.
• This competition liberates MMP9, suggesting a novel regulatory mechanism.

Conclusions:

• Alternative splicing and polyadenylation generate RECK isoforms with opposing functions in cell migration.
• The short RECK isoform promotes cell migration by interfering with canonical RECK-MMP9 interactions.
• This study reveals a new paradigm for how alternative splicing regulates cell motility from a single gene locus.