Isolation and characterization of a cDNA that encodes mouse fibroblast tropomyosin isoform 2.

1988/12/01 by Keizo Takenaga, Yohko Nakamura, Ken Tokunaga +2 · 3 citations
Biochemistry, Genetics and Molecular Biology · Medicine · #RNA and protein synthesis mechanisms #Peptidase Inhibition and Analysis #RNA Research and Splicing #Biology #Molecular biology #Tropomyosin #Complementary DNA #Gene isoform #Fibroblast #Amino acid #Alternative splicing #Skeletal muscle #cDNA library #Peptide sequence #Messenger RNA #RNA splicing #clone (Java method) #Gene #Cell culture #RNA #Actin #Biochemistry #Genetics #Anatomy

paper · doi:10.1128/mcb.8.12.5561

openalex publication_date 1988/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26

Abstract

We isolated and characterized a cDNA clone encoding tropomyosin isoform 2 (TM2) from a mouse fibroblast cDNA library. TM2 was found to contain 284 amino acids and was closely related to the rat smooth and skeletal muscle alpha-TMs and the human fibroblast TM3. The amino acid sequence of TM2 showed a nearly complete match with that of human fibroblast TM3 except for the region from amino acids 189 to 213, the sequence of which was identical to those of rat smooth and skeletal muscle alpha-TMs. These results suggest that TM2 is expressed from the same gene that encodes the smooth muscle alpha-TM, the skeletal muscle alpha-TM, and TM3 via an alternative RNA-splicing mechanism. Comparison of the expression of TM2 mRNA in low-metastatic Lewis lung carcinoma P29 cells and high-metastatic D6 cells revealed that it was significantly less in D6 cells than in P29 cells, supporting our previous observations (K. Takenaga, Y. Nakamura, and S. Sakiyama, Mol. Cell. Biol. 8:3934-3937, 1988) at the protein level.

Citations

• Alpha-tropomyosin gene organization. Alternative splicing of duplicated isotype-specific exons accounts for the production of smooth and striated muscle isoforms.
• Differential expression of a tropomyosin isoform in low- and high-metastatic Lewis lung carcinoma cells.
• Tropomyosin binding to F‐actin protects the F‐actin from disassembly by brain actin‐depolymerizing factor (ADF)
• Tropomyosin is decreased in transformed cells.
• Comparison of α-tropomyosin sequences from smooth and striated muscle
• DNA sequencing with chain-terminating inhibitors
• Multiple tropomyosin polypeptides in chicken embryo fibroblasts: differential repression of transcription by Rous sarcoma virus transformation.

Cited by

• The molecular basis for tropomyosin isoform diversity
• Three novel brain tropomyosin isoforms are expressed from the rat alpha-tropomyosin gene through the use of alternative promoters and alternative RNA processing.
• Tropomyosin [wikipedia]