Calcium (Ca(2+)) signals that are precisely modulated in space and time mediate a myriad of cellular processes, including contraction, excitation, growth, differentiation and apoptosis. However, study of Ca(2+) responses has been hampered by technological limitations of existing Ca(2+)-modulating tools. Here we present OptoSTIM1, an optogenetic tool for manipulating intracellular Ca(2+) levels through activation of Ca(2+)-selective endogenous Ca(2+) release-activated Ca(2+) (CRAC) channels. Using OptoSTIM1, which combines a plant photoreceptor and the CRAC channel regulator STIM1 (ref. 4), we quantitatively and qualitatively controlled intracellular Ca(2+) levels in various biological systems, including zebrafish embryos and human embryonic stem cells. We demonstrate that activating OptoSTIM1 in the CA1 hippocampal region of mice selectively reinforced contextual memory formation. The broad utility of OptoSTIM1 will expand our mechanistic understanding of numerous Ca(2+)-associated processes and facilitate screening for drug candidates that antagonize Ca(2+) signals.

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The use of sedatives and hypnotics and antidepressants including tricyclic antidepressants, selective serotonin reuptake inhibitors, and serotonin norepinephrine reuptake inhibitors appears to be related with an increased risk of falls. It is not clear if the use of antihypertensive medications is associated with the risk of falls in older people.

p63 expression may be a marker of basal/progenitor cells and a diagnostic marker in skin tumors. p63 expression is not related to p53 expression in these tumors. This study points to a putative role of survivin and hTERT in the development of certain skin cancers. In addition, our data support the concept of porokeratosis being a premalignant condition.

Protein homo-oligomerization is an important molecular mechanism in many biological processes. Therefore, the ability to control protein homo-oligomerization allows the manipulation and interrogation of numerous cellular events. To achieve this, cryptochrome 2 (CRY2) from Arabidopsis thaliana has been recently utilized for blue light-dependent spatiotemporal control of protein homo-oligomerization. However, limited knowledge on molecular characteristics of CRY2 obscures its widespread applications. Here, we identify important determinants for efficient cryptochrome 2 clustering and introduce a new CRY2 module, named ‘‘CRY2clust’’, to induce rapid and efficient homo-oligomerization of target proteins by employing diverse fluorescent proteins and an extremely short peptide. Furthermore, we demonstrate advancement and versatility of CRY2clust by comparing against previously reported optogenetic tools. Our work not only expands the optogenetic clustering toolbox but also provides a guideline for designing CRY2-based new optogenetic modules.

PurposeDNA deacetylation by histone deacetylase (HDAC) is an important mechanism involved in the oncogenic tumorigenesis of breast cancer. Previous studies have reported an association of the estrogen receptor (ER) with HDACs and demonstrated the efficacy of HDAC inhibitors for the treatment of breast cancers via in vitro experiments. In this study, we examined the association of HDAC expression with clinicopathological parameters and disease-specific survival.MethodsImmunohistochemical (IHC) analysis of HDAC1, HDAC2, HDAC3, and HDAC6 was performed using tissue microarrays in 300 invasive ductal carcinomas. IHC scoring was determined by multiplication of the intensity (0 to 3) and the proportion (0 to 4) of staining, and we classified tumors into low- and high-HDAC expression groups.ResultsHigh expression of HDAC1 was correlated with the molecular subtype (p=0.001) and human epidermal growth factor 2 (HER2) amplification (p=0.012). High expression of HDAC6 was correlated with a younger age (p<0.001), ER expression (p=0.025), progesterone receptor expression (p=0.034), molecular subtype (p=0.023), and HER2 amplification (p=0.011). High HDAC1 expression was correlated with luminal A tumors (p=0.001), while high HDAC6 expression was more common in luminal B tumors (p=0.023). Although the expression of HDACs did not exhibit prognostic significance in the entire cohort, high expression of HDAC1 and HDAC6 was associated with improved overall survival (OS) in patients with ER-positive tumors (p=0.017 and p=0.029, respectively), and high expression of HDAC2 was correlated with improved OS in ER-negative tumors (p=0.048) on univariate analysis. Furthermore, high HDAC6 expression was associated with improved disease-free survival (p=0.048) on multivariate analysis.ConclusionHDAC1 expression is significantly correlated with the molecular subtypes of tumors, with the highest expression being observed in luminal A tumors. HDAC6 is a significantly correlated with ER expression and the molecular subtype, thereby supporting the estrogen regulatory property of HDAC6. HDAC1 and HDAC6 expression are good prognostic factors for ER-positive tumors.

Intracellular membrane trafficking, which is involved in diverse cellular processes, is dynamic and difficult to study in a spatiotemporal manner. Here we report an optogenetic strategy, termed light-activated reversible inhibition by assembled trap of intracellular membranes (IM-LARIAT), that uses various Rab GTPases combined with blue-light-induced hetero-interaction between cryptochrome 2 and CIB1. In this system, illumination induces a rapid and reversible intracellular membrane aggregation that disrupts the dynamics and functions of the targeted membrane. We applied IM-LARIAT to specifically perturb several Rab-mediated trafficking processes, including receptor transport, protein sorting and secretion, and signaling initiated from endosomes. We finally used this tool to reveal different functions of local Rab5-mediated and Rab11-mediated membrane trafficking in growth cones and soma of young hippocampal neurons. Our results show that IM-LARIAT is a versatile tool that can be used to dissect spatiotemporal functions of intracellular membranes in diverse systems.

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