Expression pattern of an evolutionarily conserved splice variant in the rat Tacc2 gene

Area of Science:

• Molecular Biology
• Cell Biology
• Genetics

Background:

• The transforming acidic coiled-coil containing protein 2 (Tacc2) gene and its paralogs (Tacc1, Tacc3) are involved in centrosome function and microtubule assembly.
• Tacc2 gene produces multiple splice variants, with limited characterization of their temporal and spatial expression patterns, particularly in rats.

Purpose of the Study:

• To characterize the temporal and spatial expression patterns of Tacc2 splice variants in rats.
• To identify and analyze novel Tacc2 splice variants and understand their evolutionary origins.

Main Methods:

• Comparative sequence analysis of Tacc2 across multiple species.
• Identification and characterization of rat Tacc2 splice variants.
• Analysis of protein sequence homology and conservation.

Main Results:

• A novel, shorter rat Tacc2 splice variant (Isoform 3, 1,021 aa) was identified, distinct from the previously known long isoform (2,834 aa).
• Isoform 3 utilizes a unique first exon, resulting in a different open reading frame and predominantly expressed during developmental stages.
• The long Tacc2 isoform (Isoform 1) is mainly found in adult tissues.
• Sequence analyses suggest Isoform 3 is an ancient form conserved in mammals, birds, and amphibians, while longer isoforms evolved later in the mammalian lineage.

Conclusions:

• The newly identified Tacc2 Isoform 3 plays a significant role, particularly during development.
• Distinct expression patterns of Tacc2 isoforms suggest specialized functions in microtubule regulation.
• Understanding Tacc2 isoform evolution provides insights into the diversification of centrosome-associated proteins.