Alterations in the balance of tubulin glycylation and glutamylation in photoreceptors leads to retinal degeneration.
J Cell Sci
; 130(5): 938-949, 2017 03 01.
Article
in En
| MEDLINE
| ID: mdl-28104815
ABSTRACT
Tubulin is subject to a wide variety of posttranslational modifications, which, as part of the tubulin code, are involved in the regulation of microtubule functions. Glycylation has so far predominantly been found in motile cilia and flagella, and absence of this modification leads to ciliary disassembly. Here, we demonstrate that the correct functioning of connecting cilia of photoreceptors, which are non-motile sensory cilia, is also dependent on glycylation. In contrast to many other tissues, only one glycylase, TTLL3, is expressed in retina. Ttll3-/- mice lack glycylation in photoreceptors, which results in shortening of connecting cilia and slow retinal degeneration. Moreover, absence of glycylation results in increased levels of tubulin glutamylation in photoreceptors, and inversely, the hyperglutamylation observed in the Purkinje cell degeneration (pcd) mouse abolishes glycylation. This suggests that both posttranslational modifications compete for modification sites, and that unbalancing the glutamylation-glycylation equilibrium on axonemes of connecting cilia, regardless of the enzymatic mechanism, invariably leads to retinal degeneration.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Retinal Degeneration
/
Tubulin
/
Glutamic Acid
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Photoreceptor Cells, Vertebrate
Limits:
Animals
Language:
En
Journal:
J Cell Sci
Year:
2017
Document type:
Article
Affiliation country: