A Conditional Lethal Mutant in the Fission Yeast 26 S Protease Subunit mts3 Is Defective in Metaphase to Anaphase Transition

doi:10.1074/jbc.271.10.5704

A Conditional Lethal Mutant in the Fission Yeast 26 S Protease Subunit mts3 Is Defective in Metaphase to Anaphase Transition (*)

From the Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh EH4 2XU, Scotland, United Kingdom

^§ To whom correspondence should be addressed:
MRC Human Genetics Unit, Western General Hospital, Edinburgh EH4 2XU, Scotland, UK
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Abstract

We have isolated a conditional lethal mutant mts3 in the fission yeast Schizosaccharomyces pombe which at the permissive temperature is resistant to the mitotic poison MBC and at the restrictive temperature is defective in metaphase to anaphase transition. The predicted amino acid sequence of mts3 is 36% identical with the budding yeast gene NIN1. NIN1 cloned into a fission yeast expression vector can rescue both mts3 temperature-sensitive and null alleles demonstrating that NIN1 is the budding yeast homologue of the fission yeast mts3 gene. The phenotype of the mts3 null is identical with the mts3 ts mutant demonstrating that the phenotype of the mts3 ts mutant is due to loss of mts3 function. The deduced amino acid sequences of both mts3 and NIN1 show homology to peptide sequences obtained from subunit 14 of the 26 S protease purified from bovine or human cells.

Footnotes

↵^¶ International Scholar of the Howard Hughes Institute.
↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank(™)/EMBL Data Bank with accession number(s) X92682.
↵¹ The abbreviations used are:

DAPI

4′,6-diamidino-2-phenylindole

MBC

methylbenzimidazol-2-yl carbamate

PCR

polymerase chain reaction

FACS

fluoresence-activated cell sorter

TPR

tetratricopeptide repeat

ts

temperature-sensitive.
↵²M. Seeger, K. Ferrell, C. Gordon, and W. Dubiel, manuscript in preparation.
- Received July 21, 1995.
- Revision received December 20, 1995.