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Analysis of Cardiomyocyte Development using Immunofluorescence in Embryonic Mouse Heart
Published on: March 26, 2015
Developmental regulation of cardiac MAP4 protein expression
Daniel R Webster1, Jason M Bratcher
1Department of Cell Biology and Biochemistry, Texas Tech University HealthSciences Center, Lubbock, 79430, USA. Dan.Webster@ttuhsc.edu
Cell Motility and the Cytoskeleton
|June 13, 2006
Summary
Microtubule-associated protein 4 (MAP4) levels peak in neonatal hearts and decrease with age. This complex protein regulation is crucial for developing cardiomyocyte microtubules during heart development.
Area of Science:
- Cell Biology
- Developmental Biology
- Biochemistry
Background:
- Microtubule-associated protein 4 (MAP4) expression changes during neonatal heart development.
- Understanding MAP4's role is key to comprehending cardiomyocyte microtubule functional differentiation.
Purpose of the Study:
- To investigate MAP4 protein expression dynamics in the developing heart.
- To explore the regulatory mechanisms behind MAP4 heterogeneity.
- To determine MAP4's association with microtubules in neonatal cardiomyocytes.
Main Methods:
- Immunofluorescence and Western blotting to quantify MAP4 protein levels.
- Analysis of MAP4 electrophoretic species.
- Phosphatase treatment and phospho-specific antibody assays to assess phosphorylation.
- Microtubule co-localization studies.
Main Results:
- Total MAP4 protein levels were highest in the first postnatal week, declining to adulthood.
- Four distinct MAP4 protein species (bands 1-4) were identified.
- Three bands decreased with age at varying rates; one remained constant.
- Phosphorylation was not a major factor in MAP4 heterogeneity; alternative start sites or isoforms are likely responsible.
- Neonatal cardiomyocyte MAP4 associated with stable microtubules.
Conclusions:
- MAP4 protein expression is complexly regulated during heart development.
- Differential expression of MAP4 isoforms or alternative start sites contribute to protein heterogeneity.
- MAP4's association with stable microtubules suggests a role in neonatal cardiomyocyte microtubule organization and function.
