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Updated: Aug 12, 2026
Quantitative Analysis of Protein Expression to Study Lineage Specification in Mouse Preimplantation Embryos
Published on: February 22, 2016
Gene structure and expression of phospholemman in mouse
R C Bogaev1, L G Jia, Y M Kobayashi
1Department of Internal Medicine (Cardiovascular Division), University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA.
Abstract:
Phospholemman (PLM) is a small transmembrane cardiac protein that is the major sarcolemmal substrate for phosphorylation in response to adrenergic stimulation. PLM likely plays a role in muscle contractility and cell volume regulation through its function as a channel or a channel regulator. We are the first to describe the structure of the PLM gene and to demonstrate PLM cDNA splice variants. We cloned the murine PLM cDNA and used it as a probe to isolate the gene from a 129/SvJ genomic library. The gene contains seven introns and eight exons. The coding sequence is interrupted by five introns; the 5' untranslated region by two. Using rapid amplification of 5' cDNA ends we identified transcription start sites and four splice variants of the 5' untranslated domain. There was no TATA box or CAAT box in the putative promoter regions. The gene has several stretches of dinucleotide repeats. The 3' untranslated domains of mouse PLM cDNA clones show sequence differences not accounted for by alternative splicing. Mouse PLM shares 93, 83 and 80% amino acid identity with rat, dog, and human PLMs, respectively. Tissue expression of murine PLM parallels that in other species, being highest in heart, skeletal muscle, and liver.
Insights
Researchers characterized the phospholemman (PLM) gene, discovering its structure and multiple splice variants. This cardiac protein
Area of Science:
- Molecular Biology
- Cardiology
- Genetics
Background:
- Phospholemman (PLM) is a key cardiac sarcolemmal protein involved in muscle contractility and cell volume.
- Its role is linked to phosphorylation during adrenergic stimulation.
Purpose of the Study:
- To elucidate the structure of the phospholemman (PLM) gene.
- To identify and characterize PLM cDNA splice variants.
Main Methods:
- Cloning of murine PLM cDNA.
- Genomic library screening to isolate the PLM gene.
- Rapid amplification of 5' cDNA ends (5' RACE) to identify transcription start sites and splice variants.
Main Results:
- The murine PLM gene comprises seven introns and eight exons.
- Four splice variants of the 5' untranslated region were identified.
- No TATA or CAAT boxes were found in the promoter regions.
- Significant amino acid identity was observed between mouse PLM and homologous proteins in rat, dog, and human.
Conclusions:
- This study provides the first description of the PLM gene structure and its splice variants.
- Findings contribute to understanding PLM's function in cardiac physiology.
- High conservation across species suggests an important functional role for PLM.
