Protocol developing for identification of vegetal matrices used in ammodytes ammodytes freeze-dried venom adulteration

Presence of corn flour adulteration was detected by extracting the DNA from 25mg of freeze dried venom and using it as template in PCR amplification with zein specific primers known to be highly specific for corn species. The obtained amplicon was purified from agarose gel and sequenced in order to further confirm the presence of corn specific DNA sequences. The sequence thus obtained was uploaded in a DNA Data Base, and aligned with the reference zein sequence. The 99% of similarity between the two sequences enables us to confirm the corn flour adulteration in the analyzed venom sample

Signal recognition initiates reorganization of the presequence translocase during protein import.

The mitochondrial presequence translocase interacts with presequence-containing precursors at the intermembrane space (IMS) side of the inner membrane to mediate their translocation into the matrix. Little is known as too how these matrix-targeting signals activate the translocase in order to initiate precursor transport. Therefore, we analysed how signal recognition by the presequence translocase initiates reorganization among Tim-proteins during import. Our analyses revealed that the presequence receptor Tim50 interacts with Tim21 in a signal-sensitive manner in a process that involves the IMS-domain of the Tim23 channel. The signal-driven release of Tim21 from Tim50 promotes recruitment of Pam17 and thus triggers formation of the motor-associated form of the TIM23 complex required for matrix transport

Dual Role of Mitofilin in Mitochondrial Membrane Organization and Protein Biogenesis

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.