John Kilmartin

John Kilmartin started his career as a Ph.D. student with Max Perutz in 1965 working on CO₂ transport by haemoglobin and the Bohr effect. He prepared specifically modified haemoglobins to test whether particular amino acids, some predicted from the X-ray crystallographic structure Perutz had just solved, were involved in these effects.

In 1976 he made a change in direction working on molecular aspects of yeast mitosis, using both genetic and biochemical methods. He purified tubulin from yeast, made monoclonal anti-tubulin antibodies, and developed immunofluorescence methods for yeast. Immunofluorescent screening of temperature-sensitive mutants identified a mutant in a kinetochore protein. The biochemical approach led to highly enriched spindle poles, containing the yeast equivalent of the centrosome, the spindle pole body (SPB).

This allowed the identification of numerous components of both the spindle and the SPB, first from monoclonal antibodies then later by mass spectrometry. More recently he has been working particularly on the molecular mechanism of the duplication of the SPB, and has proposed a model of how the duplication process occurs.

I am working on the duplication of the yeast spindle pole body (SPB), the functional equivalent of the centrosome in yeast. The SPB, like the centriole in the centrosome, duplicates itself at the start of the cell cycle to produce a single exact copy.

I am looking at the role of a conserved centrin-binding protein Sfi1p in this process. Sfi1p is connected to the mother SPB at its N terminus and, after a process of C-terminal dimerization, initiates the assembly of the daughter SPB.