Molecular Characterization of a Neuronal‐Specific Protein that Stimulates the Activity of Cdk5

Shetty, K. Taranath; Kaech, Stefanie; Link, William T.; Jaffe, Howard; Flores, Christopher M.; Wray, Susan; Pant, H. C.; Beushausen, Sven

doi:10.1046/j.1471-4159.1995.64051988.x

Cited by 78 publications

(50 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It has been found that Cdk5 interacts with munc-18 in vivo and in vitro and phosphorylates munc-18 in vitro (37,38,61). Munc-18 is also present in ␤-cells where it is thought to operate as a negative regulator of exocytosis (62).…”

Section: Discussionmentioning

confidence: 99%

Cyclin-dependent Kinase 5 Promotes Insulin Exocytosis

Lilja

Yang

Webb

et al. 2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

Cyclin-dependent kinase 5 (Cdk5) is widely expressed although kinase activity has been described preferentially in neuronal systems. Cdk5 has an impact on actin polymerization during neuronal migration and neurite outgrowth and deregulation of the kinase has been implicated in the promotion of neurodegeneration. Recently it was shown that Cdk5 modulates dopamine signaling in neurons by regulating DARPP-32 function. In addition, Cdk5 phosphorylates munc-18 and synapsin I, two essential components of the exocytotic machinery. We have shown by reverse transcriptase-polymerase chain reaction, immunocytochemistry, and Western blotting that Cdk5 is present in the insulin-secreting pancreatic ␤-cell. Subcellular fractionation of isolated ␤-cells revealed a glucose-induced translocation of membrane-bound Cdk5 protein to lower density fractions. Inhibition of Cdk5 with roscovitine reduced insulin secretion with ϳ35% compared with control after glucose stimulation and with ϳ65% after depolarization with glucose and KCl. Capacitance measurements performed on single ␤-cells that expressed a dominantnegative Cdk5 mutant showed impaired exocytosis. The effect on exocytosis by Cdk5 appeared to be independent of changes in free cytoplasmic Ca 2؉ concentration. Taken together these results show that Cdk5 is present in ␤-cells and acts as a positive regulator of insulin exocytosis.Insulin is stored in secretory granules in pancreatic ␤-cells and upon stimulation with secretagogues insulin is released by exocytosis. Exocytosis has been suggested to be mediated by the same core fusion machinery that traverses intracellular membrane traffic in all cells (1-3). It was reported that the membrane fusion event required the N-ethylmaleimide sensitive factor (NSF), 1 and soluble NSF Attachment Proteins, ␣-, ␤-, and ␥-SNAP (1, 2). In addition to NSF and SNAPs, a 7 S core complex with SNAp receptors or "SNARE" proteins corresponding to the vesicle component synaptobrevin/vesicular-associated membrane protein, as well as the plasma membrane proteins SNAP-25 (synaptosomal-associated protein of 25 kDa) and syntaxin were necessary for neuronal exocytosis (3). The SNARE hypothesis proposes that the SNARE proteins form trans-complexes between adjacent membranes, thereby forcing them to proximity. After association of ␣-SNAP, the ATPase NSF completes the reaction by disassembling the SNARE complex leading to membrane bilayer mixing (3). More recently, trans-SNARE pairing and NSF activity has been suggested to act either prior to docking of vesicles or after membrane bilayer mixing (4 -9). Initially the SNARE proteins were regarded as neuron-specific. However, syntaxin, SNAP-25, synaptobrevin/ vesicular-associated membrane protein, and other synaptic proteins regulating neuronal exocytosis have also been identified in pancreatic ␤-cells, suggesting that the mechanism for insulin secretion is similar to that of neurotransmitter release from synaptic vesicles in neurons (10 -13). Regulated secretion of insulin from pancreatic ␤-cells has to be tightl...

show abstract

Section: Discussionmentioning

confidence: 99%

Cyclin-dependent Kinase 5 Promotes Insulin Exocytosis

Lilja

Yang

Webb

et al. 2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…In contrast to the ubiquitous distribution of Cdk5, the P35 transcript is present predominantly in the forebrain (Ohshima et al, 1996;Uchida et al, 1994) in cells of neuronal lineage (Delalle et al, 1997). Other activators of Cdk5 include 2 neuronspeci c proteins, the P39 protein (Tang et al, 1995), and the vesicle trafficking-associated protein, Munc-18 (Shetty et al, 1995). Interestingly, cyclin-D and cyclin-E molecules, which regulate Cdk activity in proliferating cells, bind but do not activate Cdk5 (Guidato et al, 1998;Miyajima et al, 1995;Xiong et al, 1992).…”

Section: Dk5mentioning

confidence: 99%

Expression and localization of cyclin-dependent kinase 5 in apoptotic human glioma cells

Catania¹

2001

Neuro-Oncology

View full text Add to dashboard Cite

Neuro-Oncology nA P R I L 2 0 0 1 89 Cyclin-dependent kinase 5 (Cdk5), a member of the cyclin-dependent kinase family, is expressed predominately in mature neurons and is implicated in neurite extension, neuronal migration, and neuronal differentiation. Cdk5 protein expression also has been associated with apoptosis in a number of nonneuronal model systems. In normal brain, substrates for Cdk5 include neuro lament and tau proteins. Because human tumors of glial origin can express neuronal proteins, we examined whether Cdk5 and its activator protein, P35, are present in early passage human glioblastoma multiforme (GBM) cells lines and primary tumor specimens. Here we report the expression of Cdk5 and an "active" proteolytic form of P35 in human GBM cells and demonstrate kinase activity of the holoenzyme. We also show that Cdk5 kinase activity and expression of its activator protein, P35, is increased in the human GBM cell line M059J after exposure to ionizing radiation and that P35 is localized within M059J cells undergoing apoptosis. These results suggest a possible role for Cdk5 in mediating apoptosis in human GBM cells. Neuro-Oncology 3, 89-98, 2001 (Posted to Neuro-Oncology [serial online], Doc. 00-038, February 15, 2001

show abstract

“…Like other members of the cyclin-dependent kinase family, cdk-5 activity requires association with a regulator, and recent studies have identified two homologous cdk-5 activators, p35 and p39flCksal (Ishiguro et al, 1994;Lew et al, 1994;Tsai et al, 1994;Tang et al, 1995). A further unrelated stimulator of cdk-5 activity, p67, which is identical to Munc-18, a component of synaptic vesicle fusion protein complexes, has also been described (Hata et al, 1993;Shetty et al, 1995). The relationship between p35 /p39 nck5ai and Munc-18 is unclear, and the relative potencies in stimulating cdk-5 activity by these different activators are not established.…”

mentioning

confidence: 99%

Cyclin D2 Interacts with cdk‐5 and Modulates Cellular cdk‐5/p35 Activity

Guidato

McLoughlin

Grierson

et al. 1998

Journal of Neurochemistry

View full text Add to dashboard Cite

Cyclin-dependent kinase-5 (cdk-5) is a serine! threonine kinase that displays neurone-specific activity. Experimental manipulation of cdk-5 expression in neurones has shown that cdk-5 is essential for proper development of the nervous system and, in particular, for outgrowth of neurites. Such observations suggest that cdk-5 activity must be tightly controlled during development of the nervous system. To identify possible regulators of cdk-5, we used the yeast two-hybrid system to search for proteins that interact with cdk-5. In two independent yeast transformation events, cyclin D2 interacted with cdk-5. Immunoprecipitation experiments confirmed that cyclin D2 and cdk-5 interact in mammalian cells. Cyclin D2 did not activate cdk-5 as assayed using three different substrates, which was in contrast to a known cdk-5 activator, p35. However, cyclin D2 expression led to a decrease in cdk-5/p35 activity in transfected cells. As cyclin D2 and cdk-5 are known to share overlapping patterns of expression during development of the CNS, the results presented here suggest a role for cyclin D2 in modulating cdk-5 activity in postmitotic developing neurones. Key Words: Cyclin-dependent kinase-5 -p35-Cyclin D2 -Neurofilaments-Tau.

show abstract

Molecular Characterization of a Neuronal‐Specific Protein that Stimulates the Activity of Cdk5

Cited by 78 publications

References 0 publications

Cyclin-dependent Kinase 5 Promotes Insulin Exocytosis

Cyclin-dependent Kinase 5 Promotes Insulin Exocytosis

Expression and localization of cyclin-dependent kinase 5 in apoptotic human glioma cells

Cyclin D2 Interacts with cdk‐5 and Modulates Cellular cdk‐5/p35 Activity

Contact Info

Product

Resources

About