N^6-Methyladenosine methyltransferase ZCCHC4 mediates ribosomal RNA methylation

Area of Science:

• Molecular Biology
• Epigenetics
• Cancer Research

Background:

• N⁶-Methyladenosine (m⁶A) is a prevalent RNA modification.
• While mRNA m⁶A roles are known, rRNA m⁶A methyltransferases and functions remain largely uncharacterized.

Purpose of the Study:

• To identify m⁶A methyltransferases responsible for rRNA modification.
• To elucidate the functional significance of rRNA m⁶A modifications in cellular processes and disease.

Main Methods:

• RNA immunoprecipitation followed by sequencing (RIP-seq)
• CRISPR-Cas9 gene editing for knockout studies
• Western blotting and cell proliferation assays
• Xenograft mouse models for tumor growth analysis

Main Results:

• ZCCHC4 identified as a primary methyltransferase for human 28S rRNA.
• ZCCHC4 knockout abolished 28S rRNA m⁶A modification, reduced global translation, and inhibited cell proliferation.
• ZCCHC4 overexpression observed in hepatocellular carcinoma (HCC); ZCCHC4 knockout suppressed tumor growth in vivo.

Conclusions:

• ZCCHC4 is a crucial rRNA m⁶A methyltransferase with significant roles in translation and cell proliferation.
• RRNA m⁶A modification is functionally important and implicated in hepatocellular carcinoma pathogenesis.
• ZCCHC4 represents a potential therapeutic target for HCC.