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N-myristoylated proteins, key components in intracellular signal transduction systems enabling rapid and flexible cell responses.

Hayashi N, Titani K - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2010)

Bottom Line: Thus, it has been shown that myristoylated proteins in cells regulate the signal transduction between membranes and cytoplasmic fractions.Interestingly, a large portion of the myristoylated proteins thought to take part in signal transduction between membranes and cytoplasmic fractions are included in the predicted myristoylated proteins.On the basis of our recent results, this review will highlight the multifunctional aspects of protein N-myristoylation in brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama-shi, Kanagawa Pref., 226-8501, Japan. nhayashi@bio.titech.ac.jp

ABSTRACT
N-myristoylation, one of the co- or post-translational modifications of proteins, has so far been regarded as necessary for anchoring of proteins to membranes. Recently, we have revealed that N(alpha)-myristoylation of several brain proteins unambiguously regulates certain protein-protein interactions that may affect signaling pathways in brain. Comparison of the amino acid sequences of myristoylated proteins including those in other organs suggests that this regulation is involved in signaling pathways not only in brain but also in other organs. Thus, it has been shown that myristoylated proteins in cells regulate the signal transduction between membranes and cytoplasmic fractions. An algorithm we have developed to identify myristoylated proteins in cells predicts the presence of hundreds of myristoylated proteins. Interestingly, a large portion of the myristoylated proteins thought to take part in signal transduction between membranes and cytoplasmic fractions are included in the predicted myristoylated proteins. If the proteins functionally regulated by myristoylation, a posttranslational protein modification, were understood as cross-talk points within the intracellular signal transduction system, known signaling pathways could thus be linked to each other, and a novel map of this intracellular network could be constructed. On the basis of our recent results, this review will highlight the multifunctional aspects of protein N-myristoylation in brain.

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Related in: MedlinePlus

Stoichiometric analysis using band shift assay of non-denatured gel electrophoresis revealed the formation of Ca2+/CaM-NAP22 complex with the molar ratio of 1:2. Lanes 1 and 6 are results of Ca2+/CaM and NAP22. Lanes 2, 3, 4 and 5 are results of Ca2+/CaM-NAP22 mixture with the molar ratio of 2:1, 1:1, 1:2 and 1:3, respectively. Bands 1, 2, and 3 correspond to Ca2+/CaM-NAP22 complex, NAP22 and Ca2+/CaM, respectively. In the presence of the calcium ion (A), upon the formation of the Ca2+/CaM-NAP22 complex, the isolated band of CaM disappeared, and, when the molar ratio of Ca2+/CaM and NAP22 was over 1:3, the isolated band of NAP22 appeared. In the absence of calcium ion (B), no shift was observed.
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fig05: Stoichiometric analysis using band shift assay of non-denatured gel electrophoresis revealed the formation of Ca2+/CaM-NAP22 complex with the molar ratio of 1:2. Lanes 1 and 6 are results of Ca2+/CaM and NAP22. Lanes 2, 3, 4 and 5 are results of Ca2+/CaM-NAP22 mixture with the molar ratio of 2:1, 1:1, 1:2 and 1:3, respectively. Bands 1, 2, and 3 correspond to Ca2+/CaM-NAP22 complex, NAP22 and Ca2+/CaM, respectively. In the presence of the calcium ion (A), upon the formation of the Ca2+/CaM-NAP22 complex, the isolated band of CaM disappeared, and, when the molar ratio of Ca2+/CaM and NAP22 was over 1:3, the isolated band of NAP22 appeared. In the absence of calcium ion (B), no shift was observed.

Mentions: Gel shift assay for stoichiometric analyses of the interaction between CAP-43/NAP-22 and Ca2+/CaM clearly indicated that two molecules of CAP-43/NAP-22 bound to one molecule of CaM (Fig. 5). Ca2+/CaM molecule adopted an ‘elongated’ structure that comprised two globular domains connected by a highly flexible linker.24–30) The binding of Ca2+/CaM to the target peptide induced a compact globular structure caused by the bending of the domain linker.31–33) The target peptides formed an α-helix in the complexes in a basic amphiphilic nature. Besides the traditional mechanism for the target recognition of CaM described above, other novel mechanisms were identified. It was shown that a single unique complex of Ca2+/CaM was formed with two peptides that corresponded to the C-terminal region of petunia glutamate decarboxylase (PGD). The formation of a 1:2 protein–protein complex was unusual; normally, Ca2+/CaM forms 1:1 complexes with the majority of its target proteins.34) It has previously been shown that a peptide corresponding to the N-terminal portion of the CaM-binding domain in plasma membrane calcium pump bound only to the C-terminal half of CaM, and that, in binding to the peptide, CaM did not form any of the collapsed structures observed in the previous studies.35)


N-myristoylated proteins, key components in intracellular signal transduction systems enabling rapid and flexible cell responses.

Hayashi N, Titani K - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2010)

Stoichiometric analysis using band shift assay of non-denatured gel electrophoresis revealed the formation of Ca2+/CaM-NAP22 complex with the molar ratio of 1:2. Lanes 1 and 6 are results of Ca2+/CaM and NAP22. Lanes 2, 3, 4 and 5 are results of Ca2+/CaM-NAP22 mixture with the molar ratio of 2:1, 1:1, 1:2 and 1:3, respectively. Bands 1, 2, and 3 correspond to Ca2+/CaM-NAP22 complex, NAP22 and Ca2+/CaM, respectively. In the presence of the calcium ion (A), upon the formation of the Ca2+/CaM-NAP22 complex, the isolated band of CaM disappeared, and, when the molar ratio of Ca2+/CaM and NAP22 was over 1:3, the isolated band of NAP22 appeared. In the absence of calcium ion (B), no shift was observed.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108300&req=5

fig05: Stoichiometric analysis using band shift assay of non-denatured gel electrophoresis revealed the formation of Ca2+/CaM-NAP22 complex with the molar ratio of 1:2. Lanes 1 and 6 are results of Ca2+/CaM and NAP22. Lanes 2, 3, 4 and 5 are results of Ca2+/CaM-NAP22 mixture with the molar ratio of 2:1, 1:1, 1:2 and 1:3, respectively. Bands 1, 2, and 3 correspond to Ca2+/CaM-NAP22 complex, NAP22 and Ca2+/CaM, respectively. In the presence of the calcium ion (A), upon the formation of the Ca2+/CaM-NAP22 complex, the isolated band of CaM disappeared, and, when the molar ratio of Ca2+/CaM and NAP22 was over 1:3, the isolated band of NAP22 appeared. In the absence of calcium ion (B), no shift was observed.
Mentions: Gel shift assay for stoichiometric analyses of the interaction between CAP-43/NAP-22 and Ca2+/CaM clearly indicated that two molecules of CAP-43/NAP-22 bound to one molecule of CaM (Fig. 5). Ca2+/CaM molecule adopted an ‘elongated’ structure that comprised two globular domains connected by a highly flexible linker.24–30) The binding of Ca2+/CaM to the target peptide induced a compact globular structure caused by the bending of the domain linker.31–33) The target peptides formed an α-helix in the complexes in a basic amphiphilic nature. Besides the traditional mechanism for the target recognition of CaM described above, other novel mechanisms were identified. It was shown that a single unique complex of Ca2+/CaM was formed with two peptides that corresponded to the C-terminal region of petunia glutamate decarboxylase (PGD). The formation of a 1:2 protein–protein complex was unusual; normally, Ca2+/CaM forms 1:1 complexes with the majority of its target proteins.34) It has previously been shown that a peptide corresponding to the N-terminal portion of the CaM-binding domain in plasma membrane calcium pump bound only to the C-terminal half of CaM, and that, in binding to the peptide, CaM did not form any of the collapsed structures observed in the previous studies.35)

Bottom Line: Thus, it has been shown that myristoylated proteins in cells regulate the signal transduction between membranes and cytoplasmic fractions.Interestingly, a large portion of the myristoylated proteins thought to take part in signal transduction between membranes and cytoplasmic fractions are included in the predicted myristoylated proteins.On the basis of our recent results, this review will highlight the multifunctional aspects of protein N-myristoylation in brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama-shi, Kanagawa Pref., 226-8501, Japan. nhayashi@bio.titech.ac.jp

ABSTRACT
N-myristoylation, one of the co- or post-translational modifications of proteins, has so far been regarded as necessary for anchoring of proteins to membranes. Recently, we have revealed that N(alpha)-myristoylation of several brain proteins unambiguously regulates certain protein-protein interactions that may affect signaling pathways in brain. Comparison of the amino acid sequences of myristoylated proteins including those in other organs suggests that this regulation is involved in signaling pathways not only in brain but also in other organs. Thus, it has been shown that myristoylated proteins in cells regulate the signal transduction between membranes and cytoplasmic fractions. An algorithm we have developed to identify myristoylated proteins in cells predicts the presence of hundreds of myristoylated proteins. Interestingly, a large portion of the myristoylated proteins thought to take part in signal transduction between membranes and cytoplasmic fractions are included in the predicted myristoylated proteins. If the proteins functionally regulated by myristoylation, a posttranslational protein modification, were understood as cross-talk points within the intracellular signal transduction system, known signaling pathways could thus be linked to each other, and a novel map of this intracellular network could be constructed. On the basis of our recent results, this review will highlight the multifunctional aspects of protein N-myristoylation in brain.

Show MeSH
Related in: MedlinePlus