SRBD1, a highly conserved gene required for chromosome individualization.

Area of Science:

• Molecular and Cellular Biology
• Genetics and Genomics
• Chromosomal Biology

Background:

• Essential genes with unknown functions pose challenges in understanding fundamental biological processes.
• Accurate sister chromatid segregation is vital for maintaining genomic stability during cell division.

Purpose of the Study:

• To elucidate the function of the essential gene S1 RNA-binding domain-containing protein 1 (SRBD1).
• To investigate SRBD1's role in chromosome segregation and its relationship with other cellular machinery.

Main Methods:

• Employed genetic, proteomic, and functional assays to characterize SRBD1.
• Utilized genetic screens to identify factors influencing SRBD1's requirement.
• Observed phenotypes related to chromosome segregation and decatenation.

Main Results:

• SRBD1 is identified as a DNA-binding protein and a component of the mitotic chromatid axis.
• Loss of SRBD1 leads to significant sister chromatid segregation defects, mimicking topoisomerase IIα (TOP2A) dysfunction.
• SRBD1's function is dependent on condensin II and is critical during prophase for chromosome condensation.

Conclusions:

• SRBD1 plays a critical role in safeguarding the decatenation process during prophase.
• This function of SRBD1 prevents the formation of complex DNA structures that impede chromosome segregation.
• SRBD1 is essential for preventing severe chromosome missegregations, thereby maintaining genomic integrity.