In eukaryotic cells, mitochondria and the endoplasmic reticulum (ER) form close contacts at mitochondria-associated ER membranes (MAMs), which are involved in diverse cellular processes. The outer mitochondrial membrane protein Fis1, known for its role in mitochondrial fission, has been reported to interact with the ER-resident protein Bap31. Here, we present crystal structures of the cytosolic domain of human Fis1 in two distinct conformations, along with a co-crystal structure of Fis1 bound to the C-terminal region of the Bap31_vDED domain.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2024
Serine phosphorylations on insulin receptor substrate 1 (IRS-1) by diverse kinases aoccur widely during obesity-, stress-, and inflammation-induced conditions in models of insulin resistance and type 2 diabetes. In this study, we define a region within the human IRS-1, which is directly C-terminal to the PTB domain encompassing numerous serine phosphorylation sites including Ser307 (mouse Ser302) and Ser312 (mouse 307) creating a phosphorylation insulin resistance (PIR) domain. We demonstrate that the IRS-1 PTB-PIR with its unphosphorylated serine residues interacts with the insulin receptor (IR) but loses the IR-binding when they are phosphorylated.
View Article and Find Full Text PDFEffectively targeting cancer stemness is essential for successful cancer therapy. Recent studies have revealed that , a pluripotent stem cell factor, significantly contributes to cancer stem cell (CSC)-like characteristics closely associated with cancer malignancy. However, its contradictory impact on patient survival in specific cancer types, including lung adenocarcinoma (LUAD), underscores the need for more comprehensive research to clarify its functional effect on cancer stemness.
View Article and Find Full Text PDFBreast cancer has a high risk of recurrence and distant metastasis after remission. Controlling distant metastasis is important for reducing breast cancer mortality, but accomplishing this goal remains elusive. In this study, we investigated the molecular pathways underlying metastasis using cells that mimic the breast cancer distant metastasis process.
View Article and Find Full Text PDFAberrant tyrosine-protein kinase Mer (MerTK) expression triggers prosurvival signaling and contributes to cell survival, invasive motility, and chemoresistance in many kinds of cancers. In addition, recent reports suggested that MerTK could be a primary target for abnormal platelet aggregation. Consequently, MerTK inhibitors may promote cancer cell death, sensitize cells to chemotherapy, and act as new antiplatelet agents.
View Article and Find Full Text PDFCancers (Basel)
September 2020
Octamer-binding transcription factor 4 (Oct4) plays an important role in maintaining pluripotency in embryonic stem cells and is closely related to the malignancies of various cancers. Although posttranslational modifications of Oct4 have been widely studied, most of these have not yet been fully characterized, especially in cancer. In this study, we investigated the role of phosphorylation of serine 236 of OCT4 [OCT4 (S236)] in human germ cell tumors (GCTs).
View Article and Find Full Text PDFCancers (Basel)
September 2019
Background: Cancers with copy-gain drug-target genes are excellent candidates for targeted therapy. In order to search for new predictive marker genes, we investigated the correlation between sensitivity to targeted drugs and the copy gain of candidate target genes in NCI-60 cells.
Methods: For eight candidate genes showing copy gains in NCI-60 cells identified in our previous study, sensitivity to corresponding target drugs was tested on cells showing copy gains of the candidate genes.
The original article contains an error for a grant number in the Acknowledgements section.
View Article and Find Full Text PDFExp Mol Med
October 2018
Glioblastoma is a highly malignant tumor that easily acquires resistance to treatment. The stem-cell-like character (stemness) has been thought to be closely associated with the treatment resistance of glioblastoma cells. In this study, we determined that farnesyl diphosphate synthase (FDPS), a key enzyme in isoprenoid biosynthesis, plays an important role in maintaining glioblastoma stemness.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2018
Germ cell tumours (GCTs) are one of the most threatening malignancies in young men and women. Although several reports have suggested the importance of OCT4 in human GCTs, its role has not been clearly investigated on a molecular level. In this study, we revealed GCT-specific direct transcriptional target genes of OCT4.
View Article and Find Full Text PDFThe exocyst, an octameric protein complex consisting of Exoc1 through Exoc8, was first determined to regulate exocytosis by targeting vesicles to the plasma membrane in yeast to mice. In addition to this fundamental role, the exocyst complex has been implicated in other cellular processes. In this study, we investigated the role of the exocyst in cochlear development and hearing by targeting EXOC5, a central exocyst component.
View Article and Find Full Text PDFNeurosci Lett
October 2016
Auditory neuropathy is a hearing disorder caused by impaired auditory nerve function. The lack of information about the pathophysiology of this disease limits early diagnosis and further treatment. Laser therapy is a novel approach to enhance nerve growth or induce axonal regeneration.
View Article and Find Full Text PDFAims: Methionine sulfoxide reductase B3 (MsrB3), which stereospecifically repairs methionine-R-sulfoxide, is an important Msr protein that is associated with auditory function in mammals. MsrB3 deficiency leads to profound congenital hearing loss due to the degeneration of stereociliary bundles and the apoptotic death of cochlear hair cells. In this study, we investigated a fundamental treatment strategy in an MsrB3 deficiency mouse model and confirmed the biological significance of MsrB3 in the inner ear using MsrB3 knockout (MsrB3(-/-)) mice.
View Article and Find Full Text PDFEYA4 and GRHL2 encode transcription factors that play an important role in regulating many developmental stages. Since EYA4 and GRHL2 were identified as the transcription factors for the DFNA10 and DFNA28, 8 EYA4 mutations and 2 GRHL2 mutations have been reported worldwide. However, these genes have been reported in few studies of the Korean population.
View Article and Find Full Text PDFMutations in COCH (coagulation factor C homology) cause autosomal-dominant nonsyndromic hearing loss with variable degrees of clinical onset and vestibular malfunction. We selected eight uncharacterized mutations and performed immunocytochemical and Western blot analyses to track cochlin through the secretory pathway. We then performed a comprehensive analysis of clinical information from DFNA9 patients with all 21 known COCH mutations in conjunction with cellular and molecular findings to identify genotype-phenotype correlations.
View Article and Find Full Text PDFInt J Pediatr Otorhinolaryngol
November 2014
Hearing loss (HL) is genetically heterogeneous and can be caused by mutations in multiple gene lesions. Pendred syndrome, caused by mutation of SLC26A4, is one of the common causes of recessive syndromic profound HL. Mitochondrial mutation is another rare cause of genetic HL, resulting in late onset sensorineural HL.
View Article and Find Full Text PDFHearing loss, which is genetically heterogeneous, can be caused by mutations in the mitochondrial DNA (mtDNA). The A1555G mutation of the 12S ribosomal RNA (rRNA) gene in the mtDNA has been associated with both aminoglycoside-induced and non-syndromic hearing loss in many ethnic populations. Here, we report for the first time the clinical and genetic characterization of nine Korean pedigrees with aminoglycoside-induced and non-syndromic hearing loss.
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