A transmembrane trap method for efficient cloning of genes encoding proteins possessing transmembrane domain

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Identifying genes for cell membrane proteins is crucial for biological research.
• Existing methods may not efficiently isolate rare or specific transmembrane protein-encoding genes.

Purpose of the Study:

• To develop and validate a novel cloning strategy for isolating cDNAs encoding proteins with hydrophobic transmembrane regions.
• To demonstrate the efficacy of this method in identifying cytokine receptor genes.

Main Methods:

• Development of the "transmembrane (TM) trap method" using a specialized vector for cell surface expression of CD4 fusion protein.
• Cloning of cDNAs in-frame with correct orientation to facilitate selection based on transmembrane sequence insertion.
• Application of the TM trap method to isolate cytokine receptor cDNAs.

Main Results:

• The TM trap method successfully isolated cDNAs for several cytokine receptors, including IL-2Rgamma, IL-3Rbeta, IL-4Ralpha, IL-5Ralpha, and IL-6Ralpha.
• The method also demonstrated potential for isolating cDNAs of intracellular molecules with transmembrane regions, such as bcl-2.
• Efficient isolation of relatively rare gene species encoding transmembrane proteins was achieved.

Conclusions:

• The TM trap method offers an efficient and versatile cloning strategy for identifying genes encoding proteins with one or more transmembrane regions.
• This technique facilitates the discovery of novel cell membrane proteins and expands the toolkit for molecular biology research.
• The method is applicable to various gene families, including cytokine receptors and intracellular transmembrane proteins.