Format

Send to

Choose Destination
See comment in PubMed Commons below
Nature. 2002 Jun 13;417(6890):758-63.

An abundant erythroid protein that stabilizes free alpha-haemoglobin.

Author information

1
The Children's Hospital of Philadelphia, Division of Hematology and the University of Pennsylvania, Philadelphia, Pennsylvania 19104-616, USA.

Abstract

The development of red blood cells (erythrocytes) is distinguished by high-level production of the oxygen carrier, haemoglobin A (HbA), a heterotetramer of alpha- and beta-haemoglobin subunits. HbA synthesis is coordinated to minimize the accumulation of free subunits that form cytotoxic precipitates. Molecular chaperones that regulate globin subunit stability, folding or assembly have been proposed to exist but have never been identified. Here we identify a protein stabilizing free alpha-haemoglobin by using a screen for genes induced by the essential erythroid transcription factor GATA-1 (refs 4, 5). Alpha Haemoglobin Stabilizing Protein (AHSP) is an abundant, erythroid-specific protein that forms a stable complex with free alpha-haemoglobin but not with beta-haemoglobin or haemoglobin A (alpha(2)beta(2)). Moreover, AHSP specifically protects free alpha-haemoglobin from precipitation in solution and in live cells. AHSP-gene-ablated mice exhibit reticulocytosis and abnormal erythrocyte morphology with intracellular inclusion bodies that stain positively for denatured haemoglobins. Hence, AHSP is required for normal erythropoiesis, probably acting to block the deleterious effects of free alpha-haemoglobin precipitation. Accordingly, AHSP gene dosage is predicted to modulate pathological states of alpha-haemoglobin excess, such as beta-thalassaemia.

Comment in

PMID:
12066189
DOI:
10.1038/nature00803
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments

    Supplemental Content

    Full text links

    Icon for Nature Publishing Group
    Loading ...
    Support Center