Project description:Biological treatment of oily sludge wastes was studied using an isolated halo-tolerant strain Pseudomonas balearica strain Z8. An oily sludge sample was obtained from oil fields of south waste of Iran and was fully characterized. The initial TPH content was 44,500 mg kg-1. The ability of Pseudomonas balearica strain Z8 in production of biosurfactant was investigated using oil displacement method. Results demonstrated that isolated strain is a biosurfactant producing bacteria. The CMC and emulsification index [E24] of produced biosurfactant were 90 mg L-1 and 44% for crude oil. Effect of operational parameters including nitrogen source, sludge/water ratio and temperature were investigated against the time. The most TPH removal of 35% was observed for nitrogen source of NH4Cl, sludge/ water ratio of 1:7 and temperature of 40 °C.
Project description:Agrin isoforms with different bioactivities are synthesized by the nerve and the muscle. Neural agrin containing an 8-amino acid insert (z8) introduced by alternative splicing is the active form that induces synaptic differentiation at the neuromuscular junction. In addition to alternative splicing, extracellular calcium is also required for the activity of neural agrin. To understand better how the activity of agrin is regulated by alternative splicing, we have applied alanine substitution mutagenesis to the z8 insert and the calcium binding site in the minimally functional AgG3z8 fragment. Single alanine substitutions in the 4th through the 7th amino acid of the z8 splice insert significantly reduced the function of agrin, in terms of acetylcholine receptor clustering activity and the affinity for binding to the muscle surface. Mutation of the asparagine at the 4th position drastically reduces bioactivity such that it is equivalent to that of muscle form AgG3z0. These reduced activity mutants also show reduced magnitudes of the calcium-induced CD spectrum change from that observed in AgG3z8 fragments, indicating that cross-talk between calcium and the z8 insert is critical for the normal activity of agrin. However, removal of Ca(2+) binding via mutation of both aspartic acids in the calcium binding site did not totally eliminate the activity of AgG3z8. These results suggest a model wherein the z8 insert is a Ca(2+)-responsive allosteric element that is essential in forming an active conformation in neuronal agrin.
Project description:Failure to achieve complete elimination of triple negative breast cancer (TNBC) stem cells after adjuvant therapy is associated with poor outcomes. Aldehyde dehydrogenase 1 (ALDH1) is a marker of breast cancer stem cells (BCSCs), and its enzymatic activity regulates tumor stemness. Identifying upstream targets to control ALDH+ cells may facilitate TNBC tumor suppression. Here, we show that KK-LC-1 determines the stemness of TNBC ALDH+ cells via binding with FAT1 and subsequently promoting its ubiquitination and degradation. This compromised the Hippo pathway and led to nuclear translocation of YAP1 and ALDH1A1 transcription. These findings identified the KK-LC-1-FAT1-Hippo-ALDH1A1 pathway in TNBC ALDH+ cells as a therapeutic target. To reverse the malignancy due to KK-LC-1 expression, we employed a novel computational approach and discovered Z839878730 (Z8) as an small-molecule inhibitor which may disrupt KK-LC-1 and FAT1 binding. We demonstrate that Z8 suppressed TNBC tumor growth via a mechanism that reactivated the Hippo pathway and decreased TNBC ALDH+ cell stemness and viability.