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Dominant De Novo Mutations in GJA1 Cause Erythrokeratodermia Variabilis et Progressiva, without Features of Oculodentodigital Dysplasia.

Boyden LM, Craiglow BG, Zhou J, Hu R, Loring EC, Morel KD, Lauren CT, Lifton RP, Bilguvar K, Yale Center for Mendelian GenomicsPaller AS, Choate KA - J. Invest. Dermatol. (2014)

Bottom Line: The severe, progressive skin disease in EKVP subjects with GJA1 mutations is distinct from limited cutaneous findings rarely found in the systemic disorder oculodentodigital dysplasia, also caused by dominant GJA1 mutations.GJA1 encodes connexin 43 (Cx43), the most widely expressed gap junction protein.These findings reveal a critical role for Cx43 in epidermal homeostasis, and they provide evidence of organ-specific pathobiology resulting from different mutations within GJA1.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA.

ABSTRACT
Genetic investigation of inherited skin disorders has informed the understanding of skin self-renewal, differentiation, and barrier function. Erythrokeratodermia variabilis et progressiva (EKVP) is a rare, inherited skin disease that is characterized by transient figurate patches of erythema, localized or generalized scaling, and frequent palmoplantar keratoderma. By using exome sequencing, we show that de novo missense mutations in GJA1 (gap junction protein alpha 1) cause EKVP. The severe, progressive skin disease in EKVP subjects with GJA1 mutations is distinct from limited cutaneous findings rarely found in the systemic disorder oculodentodigital dysplasia, also caused by dominant GJA1 mutations. GJA1 encodes connexin 43 (Cx43), the most widely expressed gap junction protein. We show that the GJA1 mutations in EKVP subjects lead to disruption of Cx43 membrane localization and aggregation within the Golgi. These findings reveal a critical role for Cx43 in epidermal homeostasis, and they provide evidence of organ-specific pathobiology resulting from different mutations within GJA1.

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Cx43 is mis-localized in EKVP(a–c) Cx43 immunolocalization was performed on tissue sections from wild-type (wt) and affected patient skin (102-1: E227D, 103-1: A44V), with Cx43 antibody in red and DAPI nuclear counterstain in blue. (a) Wild-type tissue shows primarily intercellular membrane localization of Cx43. (b–c) Affected skin shows primarily cytoplasmic localization. (d–f) Wild-type (wt) and mutant Cx43 (E227D, A44V) were HA-tagged and expressed in HeLa cells. Immunolocalization of Cx43 is red, cis-Golgi marker GM130 is green, and DAPI nuclear counterstain is blue. (d) Wild-type Cx43 localizes to intercellular junctions and does not co-localize with GM130. (e and f) The E227D and A44V mutants do not localize to intercellular junctions and accumulate in a subcellular compartment, partly co-localizing with GM130. Scale bars are 20 μm in all panels.
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Figure 6: Cx43 is mis-localized in EKVP(a–c) Cx43 immunolocalization was performed on tissue sections from wild-type (wt) and affected patient skin (102-1: E227D, 103-1: A44V), with Cx43 antibody in red and DAPI nuclear counterstain in blue. (a) Wild-type tissue shows primarily intercellular membrane localization of Cx43. (b–c) Affected skin shows primarily cytoplasmic localization. (d–f) Wild-type (wt) and mutant Cx43 (E227D, A44V) were HA-tagged and expressed in HeLa cells. Immunolocalization of Cx43 is red, cis-Golgi marker GM130 is green, and DAPI nuclear counterstain is blue. (d) Wild-type Cx43 localizes to intercellular junctions and does not co-localize with GM130. (e and f) The E227D and A44V mutants do not localize to intercellular junctions and accumulate in a subcellular compartment, partly co-localizing with GM130. Scale bars are 20 μm in all panels.

Mentions: To examine the consequence of these mutations, we immunostained tissue sections from wild-type skin and affected skin of individuals 102-1 and 103-1 with an antibody to Cx43. In contrast to normal skin, in which Cx43 primarily localizes to intercellular junctions with faint, uniform cytoplasmic staining, both E227D (102-1) and A44V (103-1) mutants do not localize to the membrane, demonstrating cytoplasmic localization (Figure 6a–c). To further explore this Cx43 localization defect, we generated expression constructs of wild-type, E227D, and A44V mutant Cx43 with a C-terminal hemagglutinin (HA) tag. Constructs were transfected into HeLa cells and immunostained with an anti-HA antibody and an antibody to the cis-Golgi marker GM130. While the wild-type protein primarily localized to intercellular junctions, both the E227D and A44V mutants aggregated in a subcellular compartment partly co-localizing with GM130, suggesting retention in the Golgi (Fig. 6d–f).


Dominant De Novo Mutations in GJA1 Cause Erythrokeratodermia Variabilis et Progressiva, without Features of Oculodentodigital Dysplasia.

Boyden LM, Craiglow BG, Zhou J, Hu R, Loring EC, Morel KD, Lauren CT, Lifton RP, Bilguvar K, Yale Center for Mendelian GenomicsPaller AS, Choate KA - J. Invest. Dermatol. (2014)

Cx43 is mis-localized in EKVP(a–c) Cx43 immunolocalization was performed on tissue sections from wild-type (wt) and affected patient skin (102-1: E227D, 103-1: A44V), with Cx43 antibody in red and DAPI nuclear counterstain in blue. (a) Wild-type tissue shows primarily intercellular membrane localization of Cx43. (b–c) Affected skin shows primarily cytoplasmic localization. (d–f) Wild-type (wt) and mutant Cx43 (E227D, A44V) were HA-tagged and expressed in HeLa cells. Immunolocalization of Cx43 is red, cis-Golgi marker GM130 is green, and DAPI nuclear counterstain is blue. (d) Wild-type Cx43 localizes to intercellular junctions and does not co-localize with GM130. (e and f) The E227D and A44V mutants do not localize to intercellular junctions and accumulate in a subcellular compartment, partly co-localizing with GM130. Scale bars are 20 μm in all panels.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430428&req=5

Figure 6: Cx43 is mis-localized in EKVP(a–c) Cx43 immunolocalization was performed on tissue sections from wild-type (wt) and affected patient skin (102-1: E227D, 103-1: A44V), with Cx43 antibody in red and DAPI nuclear counterstain in blue. (a) Wild-type tissue shows primarily intercellular membrane localization of Cx43. (b–c) Affected skin shows primarily cytoplasmic localization. (d–f) Wild-type (wt) and mutant Cx43 (E227D, A44V) were HA-tagged and expressed in HeLa cells. Immunolocalization of Cx43 is red, cis-Golgi marker GM130 is green, and DAPI nuclear counterstain is blue. (d) Wild-type Cx43 localizes to intercellular junctions and does not co-localize with GM130. (e and f) The E227D and A44V mutants do not localize to intercellular junctions and accumulate in a subcellular compartment, partly co-localizing with GM130. Scale bars are 20 μm in all panels.
Mentions: To examine the consequence of these mutations, we immunostained tissue sections from wild-type skin and affected skin of individuals 102-1 and 103-1 with an antibody to Cx43. In contrast to normal skin, in which Cx43 primarily localizes to intercellular junctions with faint, uniform cytoplasmic staining, both E227D (102-1) and A44V (103-1) mutants do not localize to the membrane, demonstrating cytoplasmic localization (Figure 6a–c). To further explore this Cx43 localization defect, we generated expression constructs of wild-type, E227D, and A44V mutant Cx43 with a C-terminal hemagglutinin (HA) tag. Constructs were transfected into HeLa cells and immunostained with an anti-HA antibody and an antibody to the cis-Golgi marker GM130. While the wild-type protein primarily localized to intercellular junctions, both the E227D and A44V mutants aggregated in a subcellular compartment partly co-localizing with GM130, suggesting retention in the Golgi (Fig. 6d–f).

Bottom Line: The severe, progressive skin disease in EKVP subjects with GJA1 mutations is distinct from limited cutaneous findings rarely found in the systemic disorder oculodentodigital dysplasia, also caused by dominant GJA1 mutations.GJA1 encodes connexin 43 (Cx43), the most widely expressed gap junction protein.These findings reveal a critical role for Cx43 in epidermal homeostasis, and they provide evidence of organ-specific pathobiology resulting from different mutations within GJA1.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA.

ABSTRACT
Genetic investigation of inherited skin disorders has informed the understanding of skin self-renewal, differentiation, and barrier function. Erythrokeratodermia variabilis et progressiva (EKVP) is a rare, inherited skin disease that is characterized by transient figurate patches of erythema, localized or generalized scaling, and frequent palmoplantar keratoderma. By using exome sequencing, we show that de novo missense mutations in GJA1 (gap junction protein alpha 1) cause EKVP. The severe, progressive skin disease in EKVP subjects with GJA1 mutations is distinct from limited cutaneous findings rarely found in the systemic disorder oculodentodigital dysplasia, also caused by dominant GJA1 mutations. GJA1 encodes connexin 43 (Cx43), the most widely expressed gap junction protein. We show that the GJA1 mutations in EKVP subjects lead to disruption of Cx43 membrane localization and aggregation within the Golgi. These findings reveal a critical role for Cx43 in epidermal homeostasis, and they provide evidence of organ-specific pathobiology resulting from different mutations within GJA1.

Show MeSH
Related in: MedlinePlus