Molecular expression and characterization of erythroid-specific 5-aminolevulinate synthase gain-of-function mutations causing X-linked protoporphyria.

ABSTRACT: X-linked protoporphyria (XLP) (MIM 300752) is a recently recognized erythropoietic porphyria due to gain-of-function mutations in the erythroid-specific aminolevulinate synthase gene (ALAS2). Previously, two exon 11 small deletions, c.1699_1670ΔAT (ΔAT) and c.1706_1709ΔAGTG (ΔAGTG), that prematurely truncated or elongated the ALAS2 polypeptide, were reported to increase enzymatic activity 20- to 40-fold, causing the erythroid accumulation of protoporphyrins, cutaneous photosensitivity and liver disease. The mutant ΔAT and ΔAGTG ALAS2 enzymes, two novel mutations, c.1734ΔG (ΔG) and c.1642C>T (p.Q548X), and an engineered deletion c.1670-1671TC>GA p.F557X were expressed, and their purified enzymes were characterized. Wild-type and ΔAGTG enzymes exhibited similar amounts of 54- and 52-kDa poly

SUBMITTER: Bishop DF 

PROVIDER: S-EPMC3592931 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature