Spitzenkörper assembly mechanisms reveal conserved features of fungal and metazoan polarity scaffolds.
Nat Commun
; 11(1): 2830, 2020 06 05.
Article
in En
| MEDLINE
| ID: mdl-32503980
ABSTRACT
The Spitzenkörper (SPK) constitutes a collection of secretory vesicles and polarity-related proteins intimately associated with polarized growth of fungal hyphae. Many SPK-localized proteins are known, but their assembly and dynamics remain poorly understood. Here, we identify protein-protein interaction cascades leading to assembly of two SPK scaffolds and recruitment of diverse effectors in Neurospora crassa. Both scaffolds are transported to the SPK by the myosin V motor (MYO-5), with the coiled-coil protein SPZ-1 acting as cargo adaptor. Neither scaffold appears to be required for accumulation of SPK secretory vesicles. One scaffold consists of Leashin-2 (LAH-2), which is required for SPK localization of the signalling kinase COT-1 and the glycolysis enzyme GPI-1. The other scaffold comprises a complex of Janus-1 (JNS-1) and the polarisome protein SPA-2. Via its Spa homology domain (SHD), SPA-2 recruits a calponin domain-containing F-actin effector (CCP-1). The SHD NMR structure reveals a conserved surface groove required for effector binding. Similarities between SPA-2/JNS-1 and the metazoan GIT/PIX complex identify foundational features of the cell polarity apparatus that predate the fungal-metazoan divergence.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Fungal Proteins
/
Cell Polarity
/
Secretory Vesicles
/
Myosin Type V
/
Neurospora crassa
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2020
Document type:
Article
Affiliation country:
Singapore