Abstract:
Tip60 is a specific member of MYST (Moz-Ybf2/Sas3-Sas2-Tip60) family of nuclear histone acetyltransferases (HAT). It is essential for cellular survival, differentiation, and metabolism. A putative canonical NLS motif between the chromo domain and the zinc finger of Tip60 was identified. Here we show evidence that Tip60 is associated with importin α as its substrate and transported from cytoplasm to the nucleus. Pull down assay revealed that Tip60 was physically associated with importin α both in vivo and in vitro. Confocal microscopic observation showed that Tip60 and importin α were co-localized with each other. The localization of Tip60 to the nuclear and its interaction with importin α was disrupted when its putative NLS motif for binding to importin α was mutated (^{219}RKRK^{222}→^{219}AAAA^{222}). However, attachment of this putative NLS motif to a cytoplasmic protein (YAP 1-210 fragment) promoted its nuclear localization. Based on transient transfection, Tip60 NLS motif mutant showed a substantial reduction in self-acetylation, HAT activity, and apoptotic ability whereas wild type Tip60 did not show such reduction. Taken together, our results demonstrate that importin α transports Tip60 from the cytoplasm to the nucleus through binding to the putative NLS motif of Tip60 for its tumor suppressing function.

Abstract:
The S-Nitrosylation of protein thiol groups by NO is a widely recognized protein modification. The treat-ment of cells with NOBF4 induces the S-nitrosylation of FE65. In this study, we present evidence showing that FE65 modified by NO (Nitric Oxide) via S-nitrosylation induces functional changes in the protein that inhibits the HAT activity of Tip60. The results of mutational analysis of FE65 demonstrated further that the cysteine residue of FE65 (Cys440) is critical to the process of S-nitrosylation. The mutation of the cysteine residue which completely ablated the S-nitrosylation of FE65 also lost its inhibitory effects on Tip60 HAT activity. Thus, our findings show, for the first time, that the novel regulation mechanism of Tip60 activity may operate via FE65 binding, which is enhanced by S-nitrosylation on the FE65 Cys440 residue. This study describes the interaction between FE65 and Tip60, which is enhanced by a posttransla-tional modification of FE65 (through S-nitrosylation) by NO, promoting the association of the FE65-Tip60 protein complex and inhibiting both the HAT activity of Tip60 and cell death.

Abstract:
The TRPV4 cation channel is expressed in a broad range of tissues and participates in the generation
of a Ca^{2+} signal and/or depolarization of membrane potential. Here, human phosphoglucomutase-
1 (PGM1), an enzyme that converts glucose-6 phosphate to glucose-1 phosphate in the glycolysis
pathway, as the first auxiliary protein of TRPV4 Ca^{2+} channels, is identified with yeast two
hybrid system, coimmunoprecipitation, confocal microscopy, and GST pull-down assays. TRPV4
forms a complex with PGM1 through its C-terminal cytoplasmic domain. Because it is demonstrated
that TRPV4 serine residue 824 (S824) is phosphorylated by serum/glucocorticoid regulated
kinase 1, we elucidate the effect of TRPV4 S824 phosphorylation on TRPV association with
PGM1. Even an inactivated mutant version of TRPV4, S824A, exhibited a decreased ability to bind
PGM1, an activated phosphomimetic mutant version of TRPV4, S824D, exhibited enhanced binding
to PGM1. Thus, formation of the TRPV4/PGM1 complex and localization of this complex to the
plasma membrane appear to be regulated by the phosphorylation status of residue S824 in TRPV4.
The newly identified interactor of TRPV4 may help the molecular pathways modulating transport
activity or glucose metabolism, respectively.

Abstract:
We first normalize the derivative Weierstrass $\wp'$-function appearing in Weierstrass equations which give rise to analytic parametrizations of elliptic curves by the Dedekind $\eta$-function. And, by making use of this normalization of $\wp'$ we associate certain elliptic curve to a given imaginary quadratic field $K$ and then generate an infinite family of ray class fields over $K$ by adjoining to $K$ torsion points of such elliptic curve. We further construct some ray class invariants of imaginary quadratic fields by utilizing singular values of the normalization of $\wp'$, as the $y$-coordinate in the Weierstrass equation of this elliptic curve, which would be a partial result for the Lang-Schertz conjecture of constructing ray class fields over $K$ by means of the Siegel-Ramachandra invariant.

Abstract:
Let $K$ be an imaginary quadratic field and $\mathcal{O}_K$ be its ring of integers. Let $h_E$ be the Weber function on certain elliptic curve $E$ with complex multiplication by $\mathcal{O}_K$. We show that if $N$ ($>1$) is an integer prime to $6$, then the function $h_E$ alone generates the ray class field modulo $N\mathcal{O}_K$ over $K$ when evaluated at some $N$-torsion point of $E$.

Abstract:
We generate ring class fields of imaginary quadratic fields in terms of the special values of certain eta-quotients, which are related to the relative norms of Siegel-Ramachandra invariants. These give us minimal polynomials with relatively small coefficients from which we are able to solve certain quadratic Diophantine equations concerning non-convenient numbers.

Abstract:
We first construct Siegel invariants of some CM-fields in terms of special values of theta constants, which would be a generalization of Siegel-Ramachandra invariants of imaginary quadratic fields. And, we further describe Galois actions on these invariants.

Abstract:
Let $\varphi(\tau)=\eta((\tau+1)/2)^2/\sqrt{2\pi}e^\frac{\pi i}{4}\eta(\tau+1)$ where $\eta(\tau)$ is the Dedekind eta-function. We show that if $\tau_0$ is an imaginary quadratic number with $\mathrm{Im}(\tau_0)>0$ and $m$ is an odd integer, then $\sqrt{m}\varphi(m\tau_0)/\varphi(\tau_0)$ is an algebraic integer dividing $\sqrt{m}$. This is a generalization of Theorem 4.4 given in [B. C. Berndt, H. H. Chan and L. C. Zhang, Ramanujan's remarkable product of theta-functions, Proc. Edinburgh Math. Soc. (2) 40 (1997), no. 3, 583-612]. On the other hand, let $K$ be an imaginary quadratic field and $\theta_K$ be an element of $K$ with $\mathrm{Im}(\theta_K)>0$ which generators the ring of integers of $K$ over $\mathbb{Z}$. We develop a sufficient condition of $m$ for $\sqrt{m}\varphi(m\theta_K)/\varphi(\theta_K)$ to become a unit.

Abstract:
Let $r_Q(n)$ be the representation number of a nonnegative integer $n$ by the quaternary quadratic form $Q=x_1^2+2x_2^2+x_3^2+x_4^2+x_1x_3+x_1x_4+x_2x_4$. We first prove the identity $r_Q(p^2n)=r_Q(p^2)r_Q(n)/r_Q(1)$ for any prime $p$ different from 13 and any positive integer $n$ prime to $p$, which was conjectured in [Eum et al, A modularity criterion for Klein forms, with an application to modular forms of level 13, J. Math. Anal. Appl. 375 (2011), 28--41]. And, we explicitly determine a concise formula for the number $r_Q(n^2)$ as well for any integer $n$.

Abstract:
A mouse pulmonary hypersensitivity experimental model that mimics human asthma was developed, and electroacupuncture (EA) treatment was shown to reduce allergic inflammatory processes. In addition, we also assessed whether the beneficial effects of EA on allergic asthma could be correlated with CD4