Isolation and characterization of mouse Thy-1 genomic clones

Area of Science:

• Molecular Biology
• Immunology
• Genetics

Background:

• Thy-1 is a cell surface glycoprotein found on lymphocytes and thymocytes.
• Understanding Thy-1's structure is key to its function in immune cell interactions.

Purpose of the Study:

• To determine the nucleotide sequence of the mouse Thy-1.2 gene.
• To analyze the predicted amino acid sequence and identify functional domains.
• To compare gene organization with the rat Thy-1 gene.

Main Methods:

• Cosmid library screening for mouse Thy-1.2 gene isolation.
• Nucleotide sequencing of an EcoRI fragment.
• RNA transfer blot analysis to detect gene expression in mouse tissues.

Main Results:

• The mouse Thy-1.2 gene sequence was determined, predicting a 19 amino acid leader peptide and 112 previously known amino acids, plus 31 novel carboxyl-terminal amino acids.
• A highly hydrophobic 20 amino acid stretch was identified at the carboxyl terminus (positions 124-143).
• This hydrophobic sequence is present in poly(A)-containing RNA from brain and thymus, suggesting its role in membrane integration.

Conclusions:

• The novel hydrophobic carboxyl terminus likely anchors the Thy-1.2 molecule to the plasma membrane.
• The mouse Thy-1.2 gene is organized into three exons.
• Mouse and rat Thy-1 genes share similar organization and encode a conserved transmembrane segment.