A masked NES in INI1/hSNF5 mediates hCRM1-dependent nuclear export: implications for tumorigenesis.

INI1 (integrase interactor 1)/hSNF5 is a component of the mammalian SWI/SNF complex and a tumor suppressor mutated in malignant rhabdoid tumors (MRT). We have identified a nuclear export signal (NES) in the highly conserved repeat 2 domain of INI1 that is unmasked upon deletion of a downstream sequence. Mutation of conserved hydrophobic residues within the NES, as well as leptomycin B treatment abrogated the nuclear export. Full-length INI1 specifically associated with hCRM1/exportin1 in vivo and in vitro. A mutant INI1 [INI1(1-319) delG950] found in MRT lacking the 66 C-terminal amino acids mislocalized to the cytoplasm. Full-length INI1 but not the INI1(1-319 delG950) mutant caused flat cell formation and cell cycle arrest in cell lines derived from MRT. Disruption of the NES in the delG950 mutant caused nuclear localization of the protein and restored its ability to cause cell cycle arrest. These observations demonstrate that INI1 has a masked NES that mediates regulated hCRM1/exportin1-dependent nuclear export and we propose that mutations that cause deregulated nuclear export of the protein could lead to tumorigenesis.     

Two sesquiterpene lactones of Calea ternifolia var. Calyculata

Chemical analysis of Calea ternifolia var. calyculata yielded the known sesquiterpene lactone calein A, as well as two new modified heliangolid     

Ultrastructure of acapsular mutant Cryptococcus neoformans cap 67 and monosaccharide composition of cell extracts

Acapsular mutant Cryptococcus neoformans cap 67 was grown in Pine's citrate broth medium for 3 days and the cells then transferred to a nitrogen-free medium for 6 days. The cells were subjected to a four stage extraction with buffered Triton-X1OO, cold dilute alkaline borohydride, hot dilute acetic acid, and a second alkaline extraction. Galactoxylomannan antigens were recovered from the culture supernates of both 3 day old and 9 day-old yeast cells. The alkaline extracts contained water-soluble galactoxylomannan and a water-insoluble glucan. Dilute acid treatment released a minor amount of carbohydrate from the cells. The second alkaline extraction yielded increased amounts of glucan and galactoxylomannan from the 9 day-old cells. Soluble non-dialyzable cell extracts were antigenically identical in immunodiffusion with the culture supernate antigens. After the extraction sequence, all of the galactose, xylose, and mannose were removed from the cells. The walls retained their shape after extraction but their layers were loosened. Cells resuspended in nitrogen-free medium for six days developed thickened walls with alternating electron-dense and electronlucent layers. The major constituent of the thickened 9 day-old cell walls was glucose, only 5% glucosamine was detected.     

Functional corticotropin-releasing factor receptors in neonatal rat spinal cord

The present study localized corticotropin-releasing factor (CRF) receptors and studied the actions of CRF in the neonatal rat spinal cord preparation. Lumbar CRF receptors were present in highest concentrations in laminae I and II with progressively lower concentrations in lamina IX and intermediate and central zones respectively. CRF directly and indirectly depolarized lumbar motoneurons in a concentration-related manner and the putative receptor antagonist, alpha helical oCRF(9–41), partially blocked the depolarizing response to CRF. The electrophysiological responses to CRF and the distribution of receptors within the spinal cord suggest that CRF may play a physiological role in regulating spinal cord reflex function.     

Zum problem der vitalen Struktur des Zellkernes

Ohne Zusammenfassung     

Screening Preeclamptic Cord Plasma for Proteins Associated with Decreased Breast Cancer Susceptibility

Preeclampsia, a complication of pregnancy characterized by hypertension and proteinuria, has been found to reduce the subsequent risk for breast cancer in female offspring. As this pro- tective effect could be due to exposure to preeclampsia-specific proteins during intrauterine life, the proteomic profiles of umbilical cord blood plasma between preeclamptic and normotensive pregnancies were compared. Umbilical cord plasma samples, depleted of 14 abundant proteins, were subjected to proteomic analysis using the quantitative method of nanoACQUITY ultra performance liquid chromatography-mass spectrometry with elevated energy mode of acquisitionE （NanoUPLC-MSE）. Sixty-nine differentially expressed proteins were identified, of which 15 and 6 proteins were only detected in preeclamptic and normotensive pregnancies, respectively.Additionally, expression of 8 proteins （gelsolin, complement C5, keratin type I cytoskeletal 10, pigment epithelium-derived factor, complement factor B, complement component C7, hemoglobin subunit gamma-2 and alpha-fetoprotein） were up-regulated in preeclampsia with a fold change of 1〉 2.0 when compared to normotensive pregnancies. The identification of alpha-fetoprotein in pre- eclamptic umbilical cord blood plasma supported the validity of this screen as alpha-fetoprotein has anti-estrogenic properties and has previously been linked to preeclampsia as well as a reduced breast cancer risk. The findings of this pilot study may provide new insights into the mechanistic link between preeclampsia and potentially reduced breast cancer susceptibility in adult life.