Biology subjects

Mostert, S.

Publications and source records attributed to Mostert, S..

2 recordsLinked to original sources

bioRxiv2024

Interaction with AK2A links AIFM1 to cellular energy metabolism

Apoptosis inducing factor 1 (AIFM1) is a flavoprotein essential for mitochondrial function and biogenesis. Its interaction with MIA40, the central component of the mitochondrial disulfide relay, accounts for some, but not all effects of AIFM1 loss. Our high-confidence AIFM1 interactome revealed novel interaction partners of AIFM1. For one of these interactors, adenylate kinase 2 (AK2), an essential enzyme maintaining cellular adenine nucleotide pools, AIFM1 binding specifically stabilized the isoform AK2A via interaction with its C-terminus. High resolution cryo-EM and biochemical analyses showed that both, MIA40 and AK2A bind AIFM1s C-terminal {beta}-strand, enhancing NADH oxidoreductase activity by locking an active, dimer conformation and, in the case of MIA40, affecting the cofactor binding site. The AIFM1-AK2A interaction is crucial during respiratory conditions. We further identified ADP/ATP translocases and the ATP synthase as AIFM1 interactors, emphasizing its important regulatory role as a central, organizing platform in energy metabolism.

biochemistry↗

bioRxiv2021

LTBP1 promotes fibrillin incorporation into the extracellular matrix

LTBP1 is a large extracellular matrix protein and an associated ligand of fibrillinmicrofibrils. Knowledge of LTBP1 functions is largely limited to its role in targeting and sequestering TGF{beta} growth factors within the extracellular matrix, thereby regulating their bioavailability. However, the recent description of a wide spectrum of phenotypes in multiple tissues in patients harboring LTBP1 pathogenic variants suggests a multifaceted role of the protein in the homeostasis of connective tissues. To better understand the human pathology caused by LTBP1 deficiency it is important to investigate its functional role in extracellular matrix formation. In this study, we show that LTBP1 coordinates the incorporation of fibrillin-1 and -2 into the extracellular matrix in vitro. We also demonstrate that this function is differentially exerted by the two isoforms, the short and long forms of LTBP1. Thereby our findings uncover a novel TGF{beta}-independent LTBP1 function potentially contributing to the development of connective tissue disorders.

cell biology↗