Cryptococcus neoformans Slu7 ensures nuclear positioning during mitotic progression through RNA splicing.

Area of Science:

• Cell Biology
• Molecular Biology
• Mycology

Background:

• Nuclear positioning is crucial for cell division in budding yeasts.
• In Cryptococcus neoformans, the nucleus migrates to the daughter bud before division.
• Slu7 proteins are known spliceosome components involved in pre-mRNA splicing.

Purpose of the Study:

• To investigate the function of Cryptococcus neoformans Slu7 (CnSlu7) in cell cycle progression.
• To determine CnSlu7's role in nuclear migration and mitosis.
• To understand the molecular mechanisms underlying CnSlu7's function.

Main Methods:

• Conditional knockdown of CnSlu7 in Cryptococcus neoformans.
• Analysis of cell cycle progression, nuclear migration, and spindle positioning.
• Transcriptome analysis (RNA sequencing) to identify affected genes.
• Complementation assays using an intron-less minigene.

Main Results:

• CnSlu7 is essential for viability and efficient cell cycle progression, particularly during mitosis.
• CnSlu7 depletion causes aberrant nuclear and spindle positioning.
• Slu7 depletion affects the splicing of introns in genes encoding cell cycle regulators and cytoskeletal factors.
• Nuclear migration defects were rescued by an intron-less PAC1 minigene, indicating the importance of splicing activity.

Conclusions:

• CnSlu7 plays a critical role in regulating nuclear migration and mitosis in Cryptococcus neoformans.
• Its function is linked to the proper splicing of pre-mRNAs encoding essential cell cycle and cytoskeletal proteins.
• CnSlu7 ensures timely cell cycle transitions and accurate nuclear division.