Mal3, the Fission Yeast Homologue of the Human APC-interacting Protein EB-1 Is Required for Microtubule Integrity and the Maintenance of Cell Form

• DOI: 10.1083/jcb.139.3.717
• Publication Date: 2002-07-26T16:47:50Z
• Authors: Jens D. Beinhauer; Iain M. Hagan; Johannes H. Hegemann; Ursula Fleig
• Keywords: Spindle pole body; Schizosaccharomyces

Through a screen designed to isolate novel fission yeast genes required for chromosome segregation, we have identified mal3+. The mal3-1 mutation decreased the transmission fidelity of nonessential minichromosome and altered sensitivity microtubule-destabilizing drugs. Sequence analysis revealed that 35-kD Mal3 is member an evolutionary conserved protein family. Its human counterpart EB-1 was in interaction with tumour suppressor APC. able substitute complete loss mal3+ gene product suggesting two proteins might similar functions. Cells containing mal3 null allele were viable but showed variety phenotypes, including impaired control cell shape. A fusion Aequorea victoria green fluorescent led vivo visualization both cytoplasmic mitotic microtubule structures indicating association microtubules. absence abnormally short, often faint microtubules as seen by indirect antitubulin immunofluorescence. While had no gross effect on spindle morphology, overexpression compromised formation function severe growth inhibition abnormal morphology. We propose plays role regulating integrity possibly influencing their stability.