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MGRN1-dependent pigment-type switching requires its ubiquitination activity but not its interaction with TSG101 or NEDD4.

ABSTRACT: Mice lacking the E3 ubiquitin ligase mahogunin ring finger-1 (MGRN1) have a pleiotropic phenotype that includes spongiform neurodegeneration, embryonic patterning defects, and dark fur due to a defect in pigment-type switching. The only MGRN1 ubiquitination target identified to date is tumor susceptibility gene 101 (TSG101), a component of the endosomal trafficking machinery. Here, we show that MGRN1 also interacts with but does not ubiquitinate NEDD4, a HECT-domain ubiquitin ligase involved in endosomal trafficking. Using transgenesis in mice, we demonstrate that pigment-type switching likely requires MGRN1's ubiquitin ligase activity but not its ability to bind TSG101 or NEDD4. This indicates that MGRN1-dependent ubiquitination of an as-yet unidentified target protein is required for agouti-mediated melanocortin signaling.

SUBMITTER: Gunn TM

PROVIDER: S-EPMC4226269 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature

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MGRN1-dependent pigment-type switching requires its ubiquitination activity but not its interaction with TSG101 or NEDD4.

Gunn Teresa M TM Silvius Derek D Bagher Pooneh P Sun Kaihua K Walker Katherine K KK

Pigment cell & melanoma research 20130108 2

Mice lacking the E3 ubiquitin ligase mahogunin ring finger-1 (MGRN1) have a pleiotropic phenotype that includes spongiform neurodegeneration, embryonic patterning defects, and dark fur due to a defect in pigment-type switching. The only MGRN1 ubiquitination target identified to date is tumor susceptibility gene 101 (TSG101), a component of the endosomal trafficking machinery. Here, we show that MGRN1 also interacts with but does not ubiquitinate NEDD4, a HECT-domain ubiquitin ligase involved in ...[more]

PMID: 23253940

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