Casein kinase 2 reverses tail-independent inactivation of kinesin-1.
30 March 2012, 11:01 am
Kinesin Casein kinase 2 reverses tail-independent inactivation of kinesin-1. - http://www.ncbi.nlm.nih.gov/entrez... March 30 from KinesinPeeps - Comment - Like Casein kinase 2 reverses tail-independent inactivation of kinesin-1. Nat Commun. 2012;3:754 Authors: Xu J, Reddy BJ, Anand P, Shu Z, Cermelli S, Mattson MK, Tripathy SK, Hoss MT, James NS, King SJ, Huang L, Bardwell L, Gross SP Abstract Kinesin-1 is a plus-end microtubule-based motor, and defects in kinesin-based transport are linked to diseases including neurodegeneration. Kinesin can auto-inhibit via a head-tail interaction, but is believed to be active otherwise. Here we report a tail-independent inactivation of kinesin, reversible by the disease-relevant signalling protein, casein kinase 2 (CK2). The majority of initially active kinesin (native or tail-less) loses its ability to interact with microtubules in vitro, and CK2 reverses this inactivation (approximately fourfold) without altering kinesin's single motor properties. This activation pathway does not require motor phosphorylation, and is independent of head-tail auto-inhibition. In cultured mammalian cells, reducing CK2... - Steve Koch

Imox: Mixed Poisson distributions in exact solutions of Stochastic Auto-regulation Models. (arXiv:1110.2804v1 [q-bio.QM])
13 October 2011, 8:17 pm
Imox Mixed Poisson distributions in exact solutions of Stochastic Auto-regulation Models. (arXiv:1110.2804v1 [q-bio.QM]) - http://arxiv.org/abs/1110.2804 October 13 from physics updates on arXiv.org - Comment - Like In this paper we study the interplay between stochastic gene expression and system design using simple stochastic models of auto-activation and auto-inhibition. Using the Poisson Representation, a technique whose usefulness in the context of non-linear gene regulation models we elucidate, we are able to write down exact results for these feedback models in the steady state. We exploit this representation to analyze the parameter-spaces and demarcate where different behaviors including power-law, conventional bimodal, a novel bimodal with graded characteristics and sub-Poisson noise occur. Using our results, we reexamine how well the auto-inhibition and auto-activation models serve their conventional roles as paradigms for noise suppression and noise exploitation respectively. - Imox

bioinffeed: The Dynamical Mechanism of auto-inhibition of AMP-Activated Protein Kinase
21 July 2011, 3:42 pm
bioinffeed The Dynamical Mechanism of auto-inhibition of AMP-Activated Protein Kinase - http://www.ploscompbiol.org/article... July 21 from PLoS Computational Biology:... - Comment - Like

November 18, 2010
18 November 2010, 1:20 am
Science and Reason Net November 18, 2010 - http://highmagblog.blogspot.com/2010... November 18, 2010 from Research Blogging - All... - Comment - Like When you see the lovely images on the cover of a journal, you can be sure that those images are the tip of the iceberg for a cell biologist's “portfolio” of images. Today’s image complements the cover and accompanying paper in this month’s Journal of Biological Chemistry and deserves its own spotlight (yes, I’m referring to HighMag as a “spotlight”). The myosin family of actin motors is large and diverse. One myosin, Myo3A, is found in the stereocilia of the inner ear and has an unconventional structure. Quintero and colleagues recently found that the kinase domain of Myo3a autophosphorylates the motor domain, which alters the localization of Myo3A and decreases the formation of actin protrusions called filopodia in cultured cells. The authors suggest that the function and localization of Myo3A in other bundled actin structures, like stereocilia, are regulated by this auto-inhibition mechanism. Image above shows the actin-binding protein espin (purple) and a mutant form of Myo3A that... - Charles Daney