Alireza Ghamari

Fourteen-Year Experience of Prenatal Diagnosis of Thalassemia in Iran

For 14 years, Iranian scientists have worked to develop a national thalassemia prevention program. Although historically abortion was considered unacceptable in Iran, intensive consultations led to the clerical approval of induced abortion in cases with β-thalassemia major in 1997, and a nationwide prevention program with screening, counseling and prenatal diagnosis (PND) networks has been developed. This paper reports the experience from one of the two national PND reference laboratories. As one of the oldest reference laboratories, we performed a total of 906 PND in 360 couples at risk for thalassemia from 1990 to 2003. Direct and indirect mutation detection methods were applied for all cases. In total, 22 mutations were tested routinely, and an additional 30 rare mutations were identified. 208 fetuses were found to be normal, 215 fetuses had β-thalassemia major, and 435 fetuses were carriers of the trait. In 40 cases, we only defined one allele. In 8 cases, we were unable to provide any diagnosis, corresponding to 0.9%. Our data support the functionality of the Iranian β-thalassemia prevention program. The success of this system in Iran, a multiethnic and Islamic-based country, would mean that it might be applied as an adaptive system for neighboring and other Islamic countries.

Differential proteomics based on 18O labeling to determine the cyclin dependent kinase 9 interactome.

Although enzyme catalyzed 18O labeling has been used as a tool in quantitative proteomics, this type of labeling has not yielded the same impact yet as alternative techniques for quantitation like SILAC or labeling with chemical mass tags. The practical difficulties involved in 18O labeling, most importantly the occurrence of incomplete labeling and, as a result, the difficulties in data analysis and interpretation have hampered its implementation in high-throughput comparative proteomics protocols. In this paper, we have optimized the 18O labeling procedure to such an extent that complete labeling can be achieved in a routine manner. We have implemented this approach into a protein-protein interaction analysis pipeline to differentiate between bona fide interaction partners of the low-level expressing cell cycle regulator cyclin-dependent kinase 9 (Cdk9) and nonspecifically binding or background proteins. Previously known as well as novel interaction partners of Cdk9 were found, among which most notably the Mediator complex and several other proteins involved in transcriptional regulation. We show here that a differential proteomics approach based on 18O labeling provides a valuable method for high-confidence determination of protein interaction partners and is easily implemented in protein network analysis workflows.

Erythropoietin signaling regulates heme biosynthesis

Heme is required for survival of all cells, and in most eukaryotes, is produced through a series of eight enzymatic reactions. Although heme production is critical for many cellular processes, how it is coupled to cellular differentiation is unknown. Here, using zebrafish, murine, and human models, we show that erythropoietin (EPO) signaling, together with the GATA1 transcriptional target, AKAP10, regulates heme biosynthesis during erythropoiesis at the outer mitochondrial membrane. This integrated pathway culminates with the direct phosphorylation of the crucial heme biosynthetic enzyme, ferrochelatase (FECH) by protein kinase A (PKA). Biochemical, pharmacological, and genetic inhibition of this signaling pathway result in a block in hemoglobin production and concomitant intracellular accumulation of protoporphyrin intermediates. Broadly, our results implicate aberrant PKA signaling in the pathogenesis of hematologic diseases. We propose a unifying model in which the erythroid transcriptional program works in concert with post-translational mechanisms to regulate heme metabolism during normal development. DOI: http://dx.doi.org/10.7554/eLife.24767.001