SMYD3 Controls Ciliogenesis by Regulating Distinct Centrosomal Proteins and Intraflagellar Transport Trafficking

Area of Science:

• Cell Biology
• Epigenetics
• Developmental Biology

Background:

• Primary cilia are crucial microtubule-based sensory organelles involved in cell signaling and cycle progression.
• Ciliopathies, caused by primary cilia defects, are a group of developmental diseases.
• The role of the epigenetic modifier SMYD3 in ciliogenesis was previously unknown.

Purpose of the Study:

• To investigate the role of SMYD3 in the regulation of ciliogenesis.
• To determine if SMYD3 is a component of the primary cilium and affects its assembly.
• To elucidate the molecular mechanisms by which SMYD3 influences cilia formation and function.

Main Methods:

• Immunofluorescence microscopy to identify SMYD3 localization.
• CRISPR-Cas9 mediated SMYD3 knockout to assess its function.
• Western blotting and quantitative PCR to analyze protein and gene expression.
• ChIP-seq to identify SMYD3 target genes.

Main Results:

• SMYD3 is a novel component of the distal appendage, essential for centriolar appendage assembly.
• Loss of SMYD3 resulted in fewer ciliated cells and shorter, stumpy cilia.
• SMYD3 regulates the recruitment of centrosome proteins and the trafficking of intraflagellar transport proteins.
• SMYD3 directly regulates the transcription of several key cilia-associated genes.

Conclusions:

• SMYD3 is a critical driver of ciliogenesis through direct and indirect regulation of cilia components.
• SMYD3's role in cilia formation and function is relevant to understanding and potentially treating ciliopathies.
• This study identifies SMYD3 as a novel regulator of primary cilia biology.