TY - JOUR
T1 - Congenital afibrinogenemia
T2 - Intracellular retention of fibrinogen due to a novel W437G mutation in the fibrinogen Bβ-chain gene
AU - Spena, Silvia
AU - Asselta, Rosanna
AU - Duga, Stefano
AU - Malcovati, Massimo
AU - Peyvandi, Flora
AU - Mannucci, Pier Mannuccio
AU - Tenchini, Maria Luisa
PY - 2003/10/15
Y1 - 2003/10/15
N2 - Congenital afibrinogenemia is a rare autosomal recessive coagulation disorder characterised by hemorrhagic manifestations of variable entity and by severe plasma fibrinogen deficiency. Among the 31 afibrinogenemia-causing mutations so far reported, only 2 are missense mutations and both are located in the fibrinogen Bβ-chain gene. Direct sequencing of the fibrinogen gene cluster in two afibrinogenemic Iranian siblings revealed a novel homozygous T>G transversion in exon 8 (nucleotide position 8025) of the fibrinogen Bβ-chain gene. The resulting W437G missense mutation involves a highly conserved amino acid residue, located in the C-terminal globular D domain. The role of the W437G amino acid substitution on fibrinogen synthesis, folding, and secretion was assessed by in vitro expression experiments in COS-1 cells, followed by qualitative and quantitative analyses of intracellular and secreted mutant fibrinogen. Results of both pulse-chase experiments and enzyme-linked immunosorbent assays demonstrated intracellular retention of the mutant W437G fibrinogen and marked reduction of its secretion. These data, besides elucidating the pathogenetic role of the W437G mutation in afibrinogenemia, underline the importance of the Bβ-chain D domain in fibrinogen folding and secretion.
AB - Congenital afibrinogenemia is a rare autosomal recessive coagulation disorder characterised by hemorrhagic manifestations of variable entity and by severe plasma fibrinogen deficiency. Among the 31 afibrinogenemia-causing mutations so far reported, only 2 are missense mutations and both are located in the fibrinogen Bβ-chain gene. Direct sequencing of the fibrinogen gene cluster in two afibrinogenemic Iranian siblings revealed a novel homozygous T>G transversion in exon 8 (nucleotide position 8025) of the fibrinogen Bβ-chain gene. The resulting W437G missense mutation involves a highly conserved amino acid residue, located in the C-terminal globular D domain. The role of the W437G amino acid substitution on fibrinogen synthesis, folding, and secretion was assessed by in vitro expression experiments in COS-1 cells, followed by qualitative and quantitative analyses of intracellular and secreted mutant fibrinogen. Results of both pulse-chase experiments and enzyme-linked immunosorbent assays demonstrated intracellular retention of the mutant W437G fibrinogen and marked reduction of its secretion. These data, besides elucidating the pathogenetic role of the W437G mutation in afibrinogenemia, underline the importance of the Bβ-chain D domain in fibrinogen folding and secretion.
KW - Congenital afibrinogenemia
KW - Fibrinogen Bβ-chain
KW - Missense mutation
KW - Protein in vitro expression
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U2 - 10.1016/S0925-4439(03)00125-X
DO - 10.1016/S0925-4439(03)00125-X
M3 - Article
C2 - 14559115
AN - SCOPUS:1642331679
VL - 1639
SP - 87
EP - 94
JO - Biochimica et Biophysica Acta - Molecular Basis of Disease
JF - Biochimica et Biophysica Acta - Molecular Basis of Disease
SN - 0925-4439
IS - 2
ER -