Mps2

Monopolar spindle 2 (Mps2) is a spindle pole body (SPB) component in budding yeast, primarily Saccharomyces cerevisiae. The name reflects its involvement in preventing the formation of bipolar spindles when mutated, which results in a monopolar spindle phenotype. Mps2 is an integral membrane protein associated with the nuclear envelope and the SPB, the yeast counterpart to the centrosome.

Functionally, Mps2 participates in SPB duplication and insertion into the nuclear envelope during the cell cycle. It helps coordinate the remodeling events that allow a new SPB to form and become integrated with the NE, ensuring proper spindle formation for chromosome segregation. Loss or dysfunction of Mps2 disrupts SPB duplication, leading to cell cycle defects and abnormal spindle morphologies.

Mps2 operates as part of a larger network of SPB and NE components. Biochemical and genetic studies place Mps2 in a complex with other proteins involved in SPB duplication and NE anchoring, including interactions with Mps3 and Ndc1. Through these associations, Mps2 is thought to link core SPB structures to the nuclear envelope, facilitating the attachment and maturation processes necessary for a functional bipolar spindle.

Research on Mps2 contributes to the broader understanding of SPB biology, nuclear envelope remodeling, and spindle orientation in yeast. While primarily studied in Saccharomyces cerevisiae, insights from Mps2 also inform general principles of organelle inheritance and cell division in eukaryotes.