Evidence for a new, high-molecular weight isoform of protein kinase C in rat hippocampus

Sublette, Elizabeth; Naik, Meghna U.; Jiang, Xiaolan; Osten, Pavel; Valsamis, Helen; Osada, Shin‐Ichi; Ohno, Shigeo

doi:10.1016/0304-3940(93)90827-8

Cited by 16 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, in rat hippocampus a protein with an apparent molecular mass of 97 kDa reacting with an antibody against PKC y was observed. This protein was described as having properties of PKC and designated 'PKC(HMW)', 'HMW' meaning 'high molecular weight' (Sublette et al, 1993). In their work this protein was described as being associated with a postnuclear membrane fraction, whereas we find the immunoreactivity almost exclusively in the nuclear fraction (Figure 3).…”

Section: Pkc Cmentioning

confidence: 61%

Localization of non-conventional protein kinase C isoforms in bovine brain cell nuclei

Rosenberger

Shakibaei

1995

Biochemical Journal

View full text Add to dashboard Cite

Using Western blotting and immunofluorescence microscopy we detected the protein kinase C isoforms delta, epsilon and zeta in isolated cell nuclei from bovine cerebral cortex. Both protein kinase C (PKC) delta and PKC epsilon are present in higher concentrations in neuronal than in glial nuclei and are located inside the nucleus and at the nuclear envelope. There they give a punctate staining in immunofluorescence microscopy. PKC zeta is also present both in the nucleoplasm and at the nuclear envelope. PKC eta could not be detected in the cell nuclei and, even in the homogenate of cerebral cortex, this isoform is present only in very low concentrations. The antibody against PKC eta bound strongly to a nucleoplasmic protein with an apparent molecular mass of 99 kDa. The localization of non-conventional PKC isoforms at the cell nucleus strongly indicates that these isoforms are directly involved in the regulation of nuclear processes.

show abstract

Section: Pkc Cmentioning

confidence: 61%

Localization of non-conventional protein kinase C isoforms in bovine brain cell nuclei

Rosenberger

Shakibaei

1995

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…1B) was found only in trace amounts in the hippocampus (data not shown). These sizes are appropriate to the primary amino‐acid sequences of the isozymes, with the exception of PKCη, which in brain appears at a higher molecular weight than PKCη in lung (Sublette et al, 1993). Although our carboxy‐terminal antisera can detect PKM made from PKC in vitro (N. Blace and T. Sacktor, unpublished observations), no substantial amount of PKM derived from these typical isoforms was consistently observed in hippocampus (Fig.…”

Section: Resultsmentioning

confidence: 99%

Distribution of protein kinase M? and the complete protein kinase C isoform family in rat brain

et al. 2000

Self Cite

View full text Add to dashboard Cite

Protein kinase C (PKC) is a multigene family of at least ten isoforms, nine of which are expressed in brain (alpha, betaI, betaII, gamma, delta, straightepsilon, eta, zeta, iota/lambda). Our previous studies have shown that many of these PKCs participate in synaptic plasticity in the CA1 region of the hippocampus. Multiple isoforms are transiently activated in the induction phase of long-term potentiation (LTP). In contrast, a single species, zeta, is persistently activated during the maintenance phase of LTP through the formation of an independent, constitutively active catalytic domain, protein kinase Mzeta (PKMzeta). In this study, we used immunoblot and immunocytochemical techniques with isoform-specific antisera to examine the distribution of the complete family of PKC isozymes and PKMzeta in rat brain. Each form of PKC showed a widespread distribution in the brain with a distinct regional pattern of high and low levels of expression. PKMzeta, the predominant form of PKM in brain, had high levels in hippocampus, frontal and occipital cortex, striatum, and hypothalamus. In the hippocampus, each isoform was expressed in a characteristic pattern, with zeta prominent in the CA1 stratum radiatum. These results suggest that the compartmentalization of PKC isoforms in neurons may contribute to their function, with the location of PKMzeta prominent in areas notable for long-term synaptic plasticity.

show abstract

“…The antipeptide antiserum against PKC'q did not detect any proteins of the predicted molecular mass in the P3 fraction. Although a ~116-kD immunoreactive protein that may represent a high molecular size isoform of PKC'q (Sublette et al, 1993) was observed, colchicine appeared to increase rather than reduce the content of this unidentified protein (Fig. 1 B).…”

Section: Presynaptic Localization Of Pkcce Pkce and Pkc~mentioning

confidence: 93%

Identification and localization of an actin-binding motif that is unique to the epsilon isoform of protein kinase C and participates in the regulation of synaptic function.

Prekeris

Mayhew

Cooper

et al. 1996

The Journal of Cell Biology

238

188

View full text Add to dashboard Cite

Abstract. Individual isoforms of the protein kinase C (PKC) family of kinases may have assumed distinct responsibilities for the control of complex and diverse cellular functions. In this study, we show that an isoform specific interaction between PKCe and filamentous actin may serve as a necessary prelude to the enhancement of glutamate exocytosis from nerve terminals. Using a combination of cosedimentation, overlay, and direct binding assays, we demonstrate that filamentous actin is a principal anchoring protein for PKCe within intact nerve endings. The unusual stability and direct nature of this physical interaction indicate that actin filaments represent a new class of PKC-binding protein. The binding of PKCe to actin required that the kinase be activated, presumably to expose a cryptic binding site that we have identified and shown to be located between the first and second cysteine-rich regions within the regulatory domain of only this individual isoform of PKC. Arachidonic acid (AA) synergistically interacted with diacylglycerol to stimulate actin binding to PKCe. Once established, this protein-protein interaction securely anchored PKCe to the cytoskeletal matrix while also serving as a chaperone that maintained the kinase in a catalytically active conformation. Thus, actin appears to be a bifunctional anchoring protein that is specific for the PKCe isoform. The assembly of this isoform-specific signaling complex appears to play a primary role in the PKC-dependent facilitation of glutamate exocytosis.VOLUTION has conserved a fundamental mechanism that ensures the sorting and fusion of secretory vesicles upon their delivery to appropriate destinations along the secretory pathway. In many eukaryotes, however, alternative pathways have emerged in which vesicle delivery and fusion have become rigorously regulated events that are capable of manifesting use-dependent variations in the probability of their occurrence. Glutamate exocytosis is a particularly striking example of a secretory event that, in presynaptic nerve terminals, has acquired a highly evolved mechanism for regulating the efficiency of excitatory synaptic transmission. Moreover, it has been established that use-dependent changes in the reliability (Stevens and Wang, 1994) and extent (Schulz et al., 1994) of glutamate exocytosis directly participate in certain forms of synaptic plasticity.Studies from many laboratories suggest that a conditional relationship may exist between the efficiency of glutamate release and the activity of presynaptic protein

show abstract

Evidence for a new, high-molecular weight isoform of protein kinase C in rat hippocampus

Cited by 16 publications

References 12 publications

Localization of non-conventional protein kinase C isoforms in bovine brain cell nuclei

Localization of non-conventional protein kinase C isoforms in bovine brain cell nuclei

Distribution of protein kinase M? and the complete protein kinase C isoform family in rat brain

Identification and localization of an actin-binding motif that is unique to the epsilon isoform of protein kinase C and participates in the regulation of synaptic function.

Contact Info

Product

Resources

About