CNG channels. In animals the CaMBDs are located far away from the CNBD. CNG channels play a large role in plant immunity and response to pathogens or external infectious agents. They have also been implicated in apoptosis in plants. CNG ion channels are also thought to be involved in pollen development in plants, however its exact role in this mechanism is still not known. Unlike animal CNG channels, plant CNG channels have not been extensively analyzed biochemically with respect to their structure. Prokaryotes CNG ion channels share a high degree of sequence and structural similarity to mammalian CNG channels. Like mammalian CNG channels, binding of cyclic nucleotides to the CNBDs has been shown to regulate channel activity and alter the channel conformational state. Because these channels were only recently identified in spirochaeta and leptospira species, their precise physiological function remains unknown in these organisms. In combination with photoactivated adenylyl cyclases, they have been used as optogenetic tools to inhibit action potential generation in neurons. Current and future research Researchers have answered many important questions regarding CNG ion channels functions in vision and olfaction. In other physiological areas, the role of CNG channels is less defined. With technological growth, there now exists more possibilities for understanding these mechanisms. Because nitric oxide (NO) is involved in stimulating the synthesis of cGMP, further research is being conducted to understand the physiological interaction of NO with CNG channels, particularly in the covalent modification of CNG channels in OSNs. Scientists are adding on to the mechanism involved in the interaction of binding sites and interfaces of subunits. This might be nonexistent in non-cooperative CNG channels. It is also possible that binding site and gate are attached to a single subunit. In order to develop these ideas, double electron-electron resonance (DEER) and rapid fixing techniques can show these mechanistic movements. A 2007 study suggests that because of the various and complex regulatory properties in addition to the large number of CNG channels in plants, a multidisciplinary study to research plant CNG channels should be conducted. Another study in March 2011 recognizes recent reverse genetics data that has been helpful in further understanding CNG channels in plants, and also suggests that additional research be conducted to identify the upstream and downstream factors in CNGC-mediated signal transduction in plants. Scientist are speculating whether DAG directly binds with CNG channel during inhibition. It is possible that DAG may insert