The 42-kD component of the S. cerevisiae spindle pole body (SPB) localizes to the electron-dense central plaque of the SPB. We have cloned the corresponding gene SPC42 (spindle pole component) and show that it is essential. Seven temperature-sensitive (ts) mutants in SPC42 were prepared by error-prone PCR. We found that a change to a proline residue in a potential coiled-coil region of Spc42p was responsible for the ts phenotype in at least three alleles, suggesting that formation of the coiled-coil is essential in normal function. The mutant cells showed a phenotype of predominantly single or bilobed SPBs often with an accumulation of unstructured electron-dense material associated with the bridge structure adjacent to the SPB. This phenotype suggests a defect in SPB duplication. This was confirmed by examining synchronized mutant cells that lose viability when SPB duplication is attempted. Spc42p is a phosphoprotein which shows some cell cycle-regulated phosphorylation. Overexpression of Spc42p causes the formation of a disc- or dome-shaped polymer composed of phosphorylated Spc42p, which is attached to the central plaque and associated with the outer nuclear membrane. Taken together, these data suggest that Spc42p forms a polymeric layer at the periphery of the SPB central plaque which has an essential function during SPB duplication and may facilitate attachment of the SPB to the nuclear membrane.
Skip Nav Destination
Article navigation
1 March 1996
Article|
March 01 1996
Spc42p: a phosphorylated component of the S. cerevisiae spindle pole body (SPD) with an essential function during SPB duplication.
A D Donaldson,
A D Donaldson
MRC Laboratory of Molecular Biology, Cambridge, England.
Search for other works by this author on:
J V Kilmartin
J V Kilmartin
MRC Laboratory of Molecular Biology, Cambridge, England.
Search for other works by this author on:
A D Donaldson
MRC Laboratory of Molecular Biology, Cambridge, England.
J V Kilmartin
MRC Laboratory of Molecular Biology, Cambridge, England.
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1996) 132 (5): 887–901.
Citation
A D Donaldson, J V Kilmartin; Spc42p: a phosphorylated component of the S. cerevisiae spindle pole body (SPD) with an essential function during SPB duplication.. J Cell Biol 1 March 1996; 132 (5): 887–901. doi: https://doi.org/10.1083/jcb.132.5.887
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionSuggested Content
Email alerts
Advertisement
Advertisement