The Drosophila cell shape regulator c-Jun N-terminal kinase also functions as a stress-activated protein kinase.

Mammalian c-Jun N-terminal kinases (JNKs) are members of a group of stress-activated intracellular signalling molecules within the MAP kinase family. Molecular genetic analysis of a highly evolutionarily conserved Drosophila JNK homologue, DJNK, has demonstrated that this molecule plays an essential developmental role in cell shape regulation. However, it remains to be determined whether DJNK also responds to the broad range of cellular stresses and other stimuli that affect its mammalian counterpart. Here we demonstrate that c-Jun, a substrate for mammalian JNKs, is a specific substrate for DJNK and that an antiserum that cross-reacts with activated mammalian JNK at the conserved threonyl-prolyl-tyrosyl (TPY) motif within the activation loop also specifically recognises the activated form of DJNK. Using these two assays, we show that DJNK activity is stimulated in cultured cells by several treatments that activate mammalian JNKs, including addition of arsenite, vanadate and ceramide derivatives. It is therefore concluded that in addition to its essential developmental functions, DJNK plays an important role in stress responses that mirrors its mammalian counterpart.

A cluster of structural and regulatory genes for light-induced carotenogenesis in Myxococcus xanthus.

In the bacterium Myxococcus xanthus, several genes for carotenoid synthesis lie together at the carA-carB chromosomal locus and are co-ordinately activated by blue light. A 12-kb DNA stretch from wild-type M. xanthus has been sequenced that includes the entire carA-carB gene cluster. According to sequence analysis, the cluster contains 11 different genes. Intergenic distances are very short or nil (implying translational coupling), giving further support to previous evidence indicating that most (or all) of the genes in the cluster form a single operon. At the promoter region, a potential -35 site for the binding of sigma factors is found. However, the -10 region shows little similarity with analogous sites in other bacterial promoters. Five (possibly six) genes in the carA-carB operon code for enzymes acting on early or late steps of the pathway for carotenoid synthesis. Other genes in the operon show no overall similarity with previously known genes. However, peptide stretches in the predicted products of two genes exhibit strong similarity with the DNA binding domain of the MerR family of transcriptional regulators. At least one of the predicted DNA-binding domains is altered in a mutant strain affected in light-regulation of the car genes.

[Idiopathic sclerosing peritonitis (ISP). A report of a new case and a review of the literature]. / Peritonitis esclerosante idiopática (P.E.I.). Presentación de un nuevo caso y revisión de la literatura.

Idiopathic sclerosing peritonitis (I.S.P.) is a rare disease, in which the small bowel is encased in a fibrous capsule, with symptoms and signs of intestinal obstruction. A new case of I.S.P. in a 42-year-old man who underwent laparotomy and was reoperated for intestinal obstruction is presented. A jejunal fistula with a favorable outcome occurred in this case. The literature about this entity is reviewed, and 16 cases are collected. This condition is being reported more and more commonly and requires further research to elucidate its unknown mechanism.

Endobronchial hamartoma. Report of 7 cases.

Seven cases of endobronchial hamartoma are presented. Preoperative fiberoptic bronchoscopic biopsy provided the histologic diagnosis in two cases, but was inconclusive in the others. The tumor was removed by endoscopic resection (2 cases), local resection via a bronchotomy (1), lobectomy (2) or pneumonectomy (1). These six patients are alive and well 2-5 years postoperatively. The seventh patient refused treatment.