Anti-CHH antibody causes impaired hyperglycemia in Penaeus monodon

Crustacean hyperglycemic hormone (CHH) plays a major role in controlling glucose level in the haemolymph and also triggers important events during molting and reproductive cycles. In Penaeus monodon, three types of CHH, namely Pem-CHH1, Pem-CHH2 and Pem-CHH3, have been previously characterized. In this study, mouse polyclonal antibody was raised against recombinant Pem-CHH1 that was expressed in Escherichia coli. The anti-Pem-CHH1 antibody recognized all three types of Pem-CHHs but did not cross-react with either related hormone, molt-inhibiting hormone of P. monodon, or unrelated human growth hormone. The hyperglycemic activity in the extract from the eyestalk neural tissues was significantly depleted after incubating with anti-Pem-CHH antibody. Direct injection of the antibody into shrimp caused about 30-50% reduction in the haemolymph glucose level. The result demonstrates the ability of anti-Pem-CHH1 antibody to deplete the activity of CHH in vivo, and thus provides a possibility of using anti-Pem-CHH1 antibody to inhibit the hormone activity as a strategy to modulate growth and reproduction in this species.     

The purification of an erythroid protein which binds to enhancer and promoter elements of haemoglobin genes.

An erythroid nuclear protein (EF1), originally detected as a protein binding within the nuclease hypersensitive site upstream of the chicken beta H-globin gene, has been purified. This protein of 37,000-39,000 molecular weight binds to three sites within the hypersensitive region: one between the CCAAT and TATA boxes, the second (further upstream) next to a NF1 binding site, and the third adjacent to a regulatory element found in a number of beta-globin genes. The EF1 protein also binds to an erythroid-specific promoter element of the mouse alpha-globin gene and to two sites within the chicken beta A-globin enhancer. These six EF1-binding sites are related by the consensus sequence A/TGATAA/GG/C. A minor protein of molecular weight 72,000 which co-purifies with EF1 also binds to the same sequences.     

Genomic structure and promoter analysis of the mouse neutral ceramidase gene

We report here the molecular cloning of the mouse neutral ceramidase gene and its promoter analysis. The gene, composed of 27 exons ranging in size from 40 to 292 bp, spans more than 70 kb. Analysis of the 5(')-flanking region of the ceramidase genes revealed that the first exon of the gene of mouse liver was exactly the same as that of mouse kidney and Swiss 3T3 fibroblasts but completely different from that of mouse brain. The putative promoter regions of liver and brain ceramidase genes contained several well-characterized promoter elements such as GATA-2, C/EBP, and HNF3beta but lacked TATA and CAAT boxes, a typical feature of a housekeeping gene, although the expression is regulated in a tissue-specific manner. Interestingly, a GC box was exclusively found in the putative promoter of mouse liver whereas potential AP1 and AP4 binding sites were present in that of mouse brain. By a luciferase reporter gene assay, it was shown that the GC-rich region, which exists just upstream of the first exon, conferred the promoter activity in Swiss 3T3 cells.