Transient PP2A SIP complex localization to mitotic SPBs for SIN inhibition is mediated solely by the Csc1 FHA domain.
Mol Biol Cell
; 35(8): br14, 2024 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-38865179
ABSTRACT
Many organisms utilize an actin- and myosin-based cytokinetic ring (CR) to help complete cytokinesis. In Schizosaccharomyces pombe, the Septation Initiation Network (SIN) promotes proper CR function and stability. The SIN is a conserved and essential signaling network consisting of a GTPase and a cascade of kinases assembled at the spindle pole body (SPB). The PP2A SIN inhibitory phosphatase (SIP) complex related to the STRIPAK phosphatase complex is one inhibitor of SIN signaling. The SIP consists of Csc1, Csc2, Csc3, Csc4, Paa1, and the phosphatase subunit Ppa3. Here, we determine that the SIP is anchored at the SPB via the Csc1 FHA domain and that constitutive SPB localization of the SIP is lethal due to persistent SIN inhibition. Disrupting SIP docking at the SPB with a point mutation within the FHA domain or eliminating phosphatase activity by introducing a point mutation within Ppa3 resulted in intact SIP complexes without SIN inhibitory function. Lastly, we defined the unique features of Ppa3 that allow it, but not two other PP2A catalytic subunits, to incorporate into the SIP. Overall, we provide insight into how the SIP complex assembles, localizes, and functions to counteract the SIN with spatiotemporal precision during cytokinesis.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Schizosaccharomyces
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Proteínas de Schizosaccharomyces pombe
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Citocinesis
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Proteína Fosfatasa 2
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Cuerpos Polares del Huso
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Mitosis
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2024
Tipo del documento:
Article