A stop or go switch: glycogen synthase kinase 3β phosphorylation of the kinesin 1 motor domain at Ser314 halts motility without detaching from microtubules

Development ◽  
2021 ◽  
Vol 148 (24) ◽  
Author(s):  
Rupkatha Banerjee ◽  
Piyali Chakraborty ◽  
Michael C. Yu ◽  
Shermali Gunawardena

ABSTRACT It is more than 25 years since the discovery that kinesin 1 is phosphorylated by several protein kinases. However, fundamental questions still remain as to how specific protein kinase(s) contribute to particular motor functions under physiological conditions. Because, within an whole organism, kinase cascades display considerable crosstalk and play multiple roles in cell homeostasis, deciphering which kinase(s) is/are involved in a particular process has been challenging. Previously, we found that GSK3β plays a role in motor function. Here, we report that a particular site on kinesin 1 motor domain (KHC), S314, is phosphorylated by GSK3β in vivo. The GSK3β-phosphomimetic-KHCS314D stalled kinesin 1 motility without dissociating from microtubules, indicating that constitutive GSK3β phosphorylation of the motor domain acts as a STOP. In contrast, uncoordinated mitochondrial motility was observed in CRISPR/Cas9-GSK3β non-phosphorylatable-KHCS314A Drosophila larval axons, owing to decreased kinesin 1 attachment to microtubules and/or membranes, and reduced ATPase activity. Together, we propose that GSK3β phosphorylation fine-tunes kinesin 1 movement in vivo via differential phosphorylation, unraveling the complex in vivo regulatory mechanisms that exist during axonal motility of cargos attached to multiple kinesin 1 and dynein motors.

1997 ◽  
Vol 8 (10) ◽  
pp. 1889-1899 ◽  
Author(s):  
Meirav Matto-Yelin ◽  
Alastair Aitken ◽  
Shoshana Ravid

Myosin II heavy chain (MHC) specific protein kinase C (MHC-PKC), isolated from Dictyostelium discoideum, regulates myosin II assembly and localization in response to the chemoattractant cyclic AMP. Immunoprecipitation of MHC-PKC revealed that it resides as a complex with several proteins. We show herein that one of these proteins is a homologue of the 14–3-3 protein (Dd14–3-3). This protein has recently been implicated in the regulation of intracellular signaling pathways via its interaction with several signaling proteins, such as PKC and Raf-1 kinase. We demonstrate that the mammalian 14–3-3 ζ isoform inhibits the MHC-PKC activity in vitro and that this inhibition is carried out by a direct interaction between the two proteins. Furthermore, we found that the cytosolic MHC-PKC, which is inactive, formed a complex with Dd14–3-3 in the cytosol in a cyclic AMP-dependent manner, whereas the membrane-bound active MHC-PKC was not found in a complex with Dd14–3-3. This suggests that Dd14–3-3 inhibits the MHC-PKC in vivo. We further show that MHC-PKC binds Dd14–3-3 as well as 14–3-3ζ through its C1 domain, and the interaction between these two proteins does not involve a peptide containing phosphoserine as was found for Raf-1 kinase. Our experiments thus show an in vivo function for a member of the 14–3-3 family and demonstrate that MHC-PKC interacts directly with Dd14–3-3 and 14–3-3ζ through its C1 domain both in vitro and in vivo, resulting in the inhibition of the kinase.


2018 ◽  
Vol 114 (3) ◽  
pp. 195a
Author(s):  
Nurit Siegler ◽  
Alina Goldstein ◽  
Ofer Shapira ◽  
Darya Goldman ◽  
Ervin Valk ◽  
...  

Author(s):  
U. Aebi ◽  
L.E. Buhle ◽  
W.E. Fowler

Many important supramolecular structures such as filaments, microtubules, virus capsids and certain membrane proteins and bacterial cell walls exist as ordered polymers or two-dimensional crystalline arrays in vivo. In several instances it has been possible to induce soluble proteins to form ordered polymers or two-dimensional crystalline arrays in vitro. In both cases a combination of electron microscopy of negatively stained specimens with analog or digital image processing techniques has proven extremely useful for elucidating the molecular and supramolecular organization of the constituent proteins. However from the reconstructed stain exclusion patterns it is often difficult to identify distinct stain excluding regions with specific protein subunits. To this end it has been demonstrated that in some cases this ambiguity can be resolved by a combination of stoichiometric labeling of the ordered structures with subunit-specific antibody fragments (e.g. Fab) and image processing of the electron micrographs recorded from labeled and unlabeled structures.


1972 ◽  
Vol 70 (4) ◽  
pp. 741-757
Author(s):  
Otto Linèt

ABSTRACT Rat adrenal glands atrophied by the administration of cortisol acetate in vivo were used as a model for the study of early metabolic processes occurring in vitro. Atrophied adrenals incubated in the presence of 14C-leucine incorporated subnormal quantities of this amino acid per mg of protein for the first 120 min. When the incubation lasted for a total period of 180 or 240 min a supranormal rise in the 14C-leucine incorporation was observed. Similar changes occurred with some delay with regard to corticosterone production as expressed per 100 mg of tissue. No differences in 14C-leucine incorporation were observed between the control and atrophied adrenals in vivo. Homogenates from atrophied glands incorporated 14C-leucine to a greater extent than the control homogenates. The in vitro incorporation of 14C-orotic acid into the RNA was also higher in atrophied adrenals. The in vitro use of actinomycin D, cycloheximide and amphenone indicated that corticosterone production depended on the incorporation of 14C-leucine. The addition of cortisol to the incubation media markedly decreased the enhancement of 14C-lysine incorporation into the protein of atrophied adrenals. These, as well as additional results suggest rebound phenomena: once atrophic adrenals are transferred to cortisol-free media, reparative processes begin after a delay period. Such phenomena seem to be mediated by regulatory mechanisms at the adrenal level.


2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>


Author(s):  
Tamilarasi G P ◽  
Sabarees G

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.


2020 ◽  
Vol 20 (12) ◽  
pp. 1059-1073 ◽  
Author(s):  
Ahmad Abu Turab Naqvi ◽  
Gulam Mustafa Hasan ◽  
Md. Imtaiyaz Hassan

Microtubule-associated protein tau is involved in the tubulin binding leading to microtubule stabilization in neuronal cells which is essential for stabilization of neuron cytoskeleton. The regulation of tau activity is accommodated by several kinases which phosphorylate tau protein on specific sites. In pathological conditions, abnormal activity of tau kinases such as glycogen synthase kinase-3 &#946; (GSK3&#946;), cyclin-dependent kinase 5 (CDK5), c-Jun N-terminal kinases (JNKs), extracellular signal-regulated kinase 1 and 2 (ERK1/2) and microtubule affinity regulating kinase (MARK) lead to tau hyperphosphorylation. Hyperphosphorylation of tau protein leads to aggregation of tau into paired helical filaments like structures which are major constituents of neurofibrillary tangles, a hallmark of Alzheimer’s disease. In this review, we discuss various tau protein kinases and their association with tau hyperphosphorylation. We also discuss various strategies and the advancements made in the area of Alzheimer&#039;s disease drug development by designing effective and specific inhibitors for such kinases using traditional in vitro/in vivo methods and state of the art in silico techniques.


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