Université de Fribourg

VGLUT1 binding to endophilin or intersectin1 and dynamin phosphorylation in a diurnal context

Richter, Karin ; Schmutz, Isabelle ; Darna, Mahesh ; Zander, Johannes-F ; Chavan, Rohit ; Albrecht, Urs ; Ahnert-Hilger, Gudrun

In: Neuroscience, 2018, vol. 371, p. 29–37

Glutamate is concentrated into synaptic vesicles (SV) by the vesicular glutamate transporters (VGLUT) 1 and 2. VGLUTs also harbor a Na+/Pi-transport activity when residing at the plasma membrane. Here we aimed to identify whether the diurnal switches of VGLUT1 parallels interactions with or modification of endocytic proteins.VGLUT1 and dynamin bind to SH3 domains of either endophilin (Enph)...

Université de Fribourg

The nuclear receptor REV-ERBα regulates Fabp7 and modulates adult hippocampal neurogenesis

Schnell, Anna ; Chappuis, Sylvie ; Schmutz, Isabelle ; Brai, Emanuele ; Ripperger, Jürgen A. ; Schaad, Olivier ; Welzl, Hans ; Descombes, Patrick ; Alberi, Lavinia ; Albrecht, Urs

In: PLoS ONE, 2014, vol. 9, no. 6, p. e99883

The function of the nuclear receptor Rev-erbα (Nr1d1) in the brain is, apart from its role in the circadian clock mechanism, unknown. Therefore, we compared gene expression profiles in the brain between wild-type and Rev-erbα knock-out (KO) animals. We identified fatty acid binding protein 7 (Fabp7, Blbp) as a direct target of repression by REV-ERBα. Loss of Rev-erbα manifested in memory and...

Université de Fribourg

Lab mice in the field: unorthodox daily activity and effects of a dysfunctional circadian clock allele

Spoelstra, Kamiel ; Albrecht, Urs ; Schmutz, Isabelle ; Daan, Moritz ; Daan, Berte ; Rienks, Froukje ; Poletaeva, Inga ; Dell'Omo, Giacomo ; Vyssotski, Alexei ; Lipp, Hans-Peter

In: Journal of Biological Rhytms, 2011, vol. 26, no. 2, p. 118-129

Daily patterns of animal behavior are potentially of vast functional importance. Fitness benefits have been identified in nature by the association between individual timing and survival or by the fate of individuals after experimental deletion of their circadian pacemaker. The recent advances in unraveling the molecular basis of circadian timing enable new approaches to natural selection on...

Université de Fribourg

The role of clock genes and rhythmicity in the liver

Schmutz, Isabelle ; Albrecht, Urs ; Ripperger, Jürgen A.

In: Molecular and Cellular Endocrinology, 2011, p. -

The liver is the important organ to maintain energy homeostasis of an organism. To achieve this, many biochemical reactions run in this organ in a rhythmic fashion. An elegant way to coordinate the temporal expression of genes for metabolic enzymes relies in the link to the circadian timing system. In this fashion not only a maximum of synchronization is achieved, but also anticipation of daily...

Université de Fribourg

Protein phosphatase 1 (pp1) is a post-translational regulator of the mammalian circadian clock

Schmutz, Isabelle ; Wendt, Sabrina ; Schnell, Anna ; Kramer, Achim ; Mansuy, Isabelle M. ; Albrecht, Urs

In: PLoS ONE, 2011, vol. 6, no. 6, p. e21325

Circadian clocks coordinate the timing of important biological processes. Interconnected transcriptional and post-translational feedback loops based on a set of clock genes generate and maintain these rhythms with a period of about 24 hours. Many clock proteins undergo circadian cycles of post-translational modifications. Among these modifications, protein phosphorylation plays an important role...

Université de Fribourg

PERsuading nuclear receptors to dance the circadian rhythm

Ripperger, Jürgen A. ; Schmutz, Isabelle ; Albrecht, Urs

In: Cell Cycle, 2010, vol. 9, no. 13, p. 2515-2521

The recurring light/dark cycle that has a period length of about 24 hours has been internalized in various organisms in the form of a circadian clock. This clock allows a precise orchestration of biochemical and physiological processes in the body thus improving performance. Recently, we found that the clock component PERIOD2 (PER2) can coordinate transcriptional regulation of metabolic,...

Université de Fribourg

the clock genes Period 2 and Cryptochrome 2 differentially balance bone formation

Maronde, Erik ; Schilling, Arndt F. ; Seitz, Sebastian ; Schinke, Thorsten ; Schmutz, Isabelle ; Horst, Gijsbertus van der ; Amling, Michael ; Albrecht, Urs

In: PLoS One, 2010, vol. 5, no. 7, p. e11527

Background: Clock genes and their protein products regulate circadian rhythms in mammals but have also been implicated in various physiological processes, including bone formation. Osteoblasts build new mineralized bone whereas osteoclasts degrade it thereby balancing bone formation. To evaluate the contribution of clock components in this process, we investigated mice mutant in clock genes for a...

Université de Fribourg

Lack of Calbindin-D28k alters response of the murine circadian clock to light

Stadler, Frédéric ; Schmutz, Isabelle ; Schwaller, Beat ; Albrecht, Urs

In: Chronobiology International, 2010, vol. 27, no. 1, p. 68-82

A strong stimulus adjusting the circadian clock to the prevailing light-dark cycle is light. However, the circadian clock is reset by light only at specific times of the day. The mechanisms mediating such gating of light input to the CNS are not well understood. There is evidence that Ca²⁺ ions play an important role in intracellular signaling mechanisms, including signaling cascades...

Université de Fribourg

The mammalian clock component PERIOD2 coordinates circadian output by interaction with nuclear receptors

Schmutz, Isabelle ; Ripperger, Jürgen A. ; Baeriswyl-Aebischer, Stéphanie ; Albrecht, Urs

In: Genes & Development, 2010, vol. 24, p. 345-357

Mammalian circadian clocks provide a temporal framework to synchronize biological functions. To obtain robust rhythms with a periodicity of about a day, these clocks use molecular oscillators consisting of two interlocked feedback loops. The core loop generates rhythms by transcriptional repression via the Period (PER) and Cryptochrome (CRY) proteins, whereas the stabilizing loop establishes...