Insight Into the Architecture of Life: Researchers Discover Supporting Pillars of the Structure of Cellular Power Plants
ScienceDaily (Sep. 23, 2011) — Scientists at the University of Freiburg have discovered a new mechanism that is of central significance for the architecture and functioning of mitochondria, known as the power plants of the cell. With the help of chemical reactions that take place on their inner membranes, these organelles convert food into energy for the metabolism and growth of the cell. The inner mitochondrial membrane features a characteristic architecture that is essential for its role as an energy transducer. Errors in the structure of the mitochondria can lead to serious illnesses in humans, particularly illnesses affecting the muscles and nerves.
The inner mitochondrial membrane features a characteristic architecture that is essential for its role as an energy transducer. (Credit: Van der Klei/Bohnert)
The inner mitochondrial membrane forms tubular invaginations known as cristae, and these delicate generators of the power plants are surrounded by an outer mitochondrial membrane. The composition of this microstructure, which is identical in all organisms, from unicellular life forms to human beings, has remained a mystery until now. In a joint research project between the Priority Program SFB 746, the Cluster of Excellence Centre for Biological Signalling Studies (BIOSS), and the Spemann Graduate School of Biology and Medicine (SGBM), a team of scientists in Freiburg led by Dr. Martin van der Laan and Prof. Bettina Warscheid has discovered an enormous molecular machine composed of six different membrane proteins that is necessary for attaching the cristae to the envelope of the mitochondria in the unicellular model organism baker's yeast.
The study, now published in the journal Developmental Cell, demonstrates that defects in this protein complex lead to the detachment of the cristae, causing severe growth disturbances in the cell.
...
Read more here/Leia mais aqui: Science Daily
+++++
+++++
Dual Role of Mitofilin in Mitochondrial Membrane Organization and Protein Biogenesis
Karina von der Malsburg et al
1 Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
2 BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany
Summary
The mitochondrial inner membrane consists of two domains, inner boundary membrane and cristae membrane that are connected by crista junctions. Mitofilin/Fcj1 was reported to be involved in formation of crista junctions, however, different views exist on its function and possible partner proteins. We report that mitofilin plays a dual role. Mitofilin is part of a large inner membrane complex, and we identify five partner proteins as constituents of the mitochondrial inner membrane organizing system (MINOS) that is required for keeping cristae membranes connected to the inner boundary membrane. Additionally, mitofilin is coupled to the outer membrane and promotes protein import via the mitochondrial intermembrane space assembly pathway. Our findings indicate that mitofilin is a central component of MINOS and functions as a multifunctional regulator of mitochondrial architecture and protein biogenesis.
+++++
+++++
PERGUNTA CAUSTICANTE DESTE BLOGGER:
Se a mitofilina é um componente central do MINOS e funciona como um regulador [palavra teleológica???] da arquitetura [design???] mitocondrial e da biogênese da proteína, como surgiu? Mero acaso, fortuita necessidade ou design inteligente???
A cada dia que passa as pesquisas científicas revelam cada vez mais níveis de complexidade dos sistemas biológicos dos quais Darwin era completamente ignorante (limitado pelo referencial teórico e aparelhos científicos existentes).
A cada dia me convenço que a teoria do Design Inteligente não é acolhida pela Nomenklatura científica mais por razões ideológicas do naturalismo filosófico do que razões científicas.
A cada dia que passa as pesquisas científicas revelam cada vez mais níveis de complexidade dos sistemas biológicos dos quais Darwin era completamente ignorante (limitado pelo referencial teórico e aparelhos científicos existentes).
A cada dia me convenço que a teoria do Design Inteligente não é acolhida pela Nomenklatura científica mais por razões ideológicas do naturalismo filosófico do que razões científicas.
+++++
Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem ler gratuitamente este artigo da Developmental Cell e de mais 22.440 publicações científicas.
