Functional characterization of an N-terminally-truncated mitochondrial porin expressed in Neurospora crassa
| Autor: | Uliana Kovaltchouk, Sabbir Rahman Shuvo, Ayush Kumar, Abdullah Zubaer, Lynda J. Donald, William A.T. Summers, Deborah A. Court, George Hausner |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Alternative oxidase Voltage-dependent anion channel Immunology Porins Gating Mitochondrion Applied Microbiology and Biotechnology Microbiology Neurospora crassa Mitochondrial Proteins 03 medical and health sciences Genetics Voltage-Dependent Anion Channels Molecular Biology Plant Proteins Sequence Deletion 030102 biochemistry & molecular biology biology Wild type General Medicine biology.organism_classification Mitochondria 030104 developmental biology Biochemistry Porin biology.protein Oxidoreductases Bacterial outer membrane |
| Zdroj: | Canadian Journal of Microbiology. 63:730-738 |
| ISSN: | 1480-3275 0008-4166 |
| Popis: | Mitochondrial porin, which forms voltage-dependent anion-selective channels (VDAC) in the outer membrane, can be folded into a 19-β-stranded barrel. The N terminus of the protein is external to the barrel and contains α-helical structure. Targeted modifications of the N-terminal region have been assessed in artificial membranes, leading to different models for gating in vitro. However, the in vivo requirements for gating and the N-terminal segment of porin are less well-understood. Using Neurospora crassa porin as a model, the effects of a partial deletion of the N-terminal segment were investigated. The protein, ΔN2-12porin, is assembled into the outer membrane, albeit at lower levels than the wild-type protein. The resulting strain displays electron transport chain deficiencies, concomitant expression of alternative oxidase, and decreased growth rates. Nonetheless, its mitochondrial genome does not contain any significant mutations. Most of the genes that are expressed in high levels in porin-less N. crassa are expressed at levels similar to that of wild type or are slightly increased in ΔN2-12porin strains. Thus, although the N-terminal segment of VDAC is required for complete function in vivo, low levels of a protein lacking part of the N terminus are able to rescue some of the defects associated with the absence of porin. |
| Databáze: | OpenAIRE |
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