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Microvillar and ciliary defects in zebrafish lacking an actin-binding bioactive peptide amidating enzyme
Dhivya Kumar1,2, Rebecca T Thomason3,4, Maya Yankova1,5
1Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA.
Scientific Reports
|March 16, 2018
Summary
Peptidylglycine α-amidating monooxygenase (PAM) is crucial for cell structure. Lack of PAM disrupts microvilli and cilia formation by affecting the actin cytoskeleton, leading to developmental defects.
Area of Science:
- Cell Biology
- Developmental Biology
- Biochemistry
Background:
- The formation of cellular extensions like microvilli and cilia is vital for cell function but not fully understood.
- Peptidylglycine α-amidating monooxygenase (PAM) is an enzyme involved in peptide synthesis, found in cilia, and essential for ciliogenesis.
- Altered PAM levels impact the actin cytoskeleton and secretion in mammalian cells.
Purpose of the Study:
- To investigate the role of PAM in embryonic development and its impact on microvilli and ciliogenesis.
- To elucidate the molecular mechanisms by which PAM interacts with the actin cytoskeleton.
Main Methods:
- Utilized zebrafish (Danio rerio) as a model organism to study the effects of PAM deficiency.
- Examined microvilli and ciliogenesis in PAM-deficient zebrafish embryos and mouse tracheal epithelial cells.
- Performed biochemical assays to analyze the interaction between PAM and actin filaments.
Main Results:
- Zebrafish lacking PAM exhibited a lethal edematous phenotype, loss of microvilli, and impaired ciliogenesis.
- PAM deficiency in Chlamydomonas led to actin cytoskeleton reorganization and altered actin paralogue expression.
- The cytosolic C-terminal domain of PAM directly interacts with filamentous actin.
Conclusions:
- PAM plays a critical role in organizing the actin cytoskeleton during development.
- This organization by PAM is essential for proper microvillus formation and ciliogenesis.
- PAM's interaction with actin provides a novel mechanism linking peptide metabolism to cytoskeletal dynamics.
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