Disc-associated proteins mediate the unusual hyperstability of the ventral disc in Giardia lamblia.
J Cell Sci
; 133(16)2020 08 27.
Article
in En
| MEDLINE
| ID: mdl-32661087
ABSTRACT
Giardia lamblia, a widespread parasitic protozoan, attaches to the host gastrointestinal epithelium by using the ventral disc, a complex microtubule (MT) organelle. The 'cup-like' disc is formed by a spiral MT array that scaffolds numerous disc-associated proteins (DAPs) and higher-order protein complexes. In interphase, the disc is hyperstable and has limited MT dynamics; however, it remains unclear how DAPs confer these properties. To investigate mechanisms of hyperstability, we confirmed the disc-specific localization of over 50 new DAPs identified by using both a disc proteome and an ongoing GFP localization screen. DAPs localize to specific disc regions and many lack similarity to known proteins. By screening 14 CRISPRi-mediated DAP knockdown (KD) strains for defects in hyperstability and MT dynamics, we identified two strains - DAP5188KD and DAP6751KD -with discs that dissociate following high-salt fractionation. Discs in the DAP5188KD strain were also sensitive to treatment with the MT-polymerization inhibitor nocodazole. Thus, we confirm here that at least two of the 87 known DAPs confer hyperstable properties to the disc MTs, and we anticipate that other DAPs contribute to disc MT stability, nucleation and assembly.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Giardia lamblia
Type of study:
Risk_factors_studies
Language:
En
Journal:
J Cell Sci
Year:
2020
Type:
Article
Affiliation country:
United States