P/Q-type voltage-dependent calcium channels play key roles in transmitter release, integration of dendritic signals, generation of dendritic spikes, and gene expression. High intracellular calcium concentration transient produced by these channels is restricted to tens to hundreds of nanometers from the channels. Therefore, precise localization of these channels along the plasma membrane was long sought to decipher how each neuronal cell function is controlled. Here, we analyzed the distribution of Cav2.1 subunit of the P/Q-type channel using highly sensitive SDS-digested freeze-fracture replica labeling in the rat cerebellar Purkinje cells. The labeling efficiency was such that the number of immunogold particles in each parallel fiber active zone was comparable to that of functional channels calculated from previous reports. Two distinct patterns of Cav2.1 distribution, scattered and clustered, were found in Purkinje cells. The scattered Cav2.1 had a somatodendritic gradient with the density of immunogold particles increasing 2.5-fold from soma to distal dendrites. The other population with 74-fold higher density than the scattered particles was found within clusters of intramembrane particles on the P-face of soma and primary dendrites. Both populations of Cav2.1 were found as early as P3 and increased in the second postnatal week to a mature level. Using double immunogold labeling, we found that virtually all of the Cav2.1 clusters were colocalized with two types of calcium-activated potassium channels, BK and SK2, with the nearest neighbor distance of ~40 nm. Calcium nanodomain created by the opening of Cav2.1 channels likely activates the two channels that limit the extent of depolarization.

The development of gp120 targeted human immunodeficiency virus (HIV) drug has improved antiretroviral therapies owing to its effects on attachment to target cells.

Papua and West Papua provinces have the highest prevalence rate of human immunodeficiency virus type 1 (HIV-1) infection in Indonesia; however, data on the molecular epidemiology of HIV-1 are limited. We conducted a genotypic study on HIV-1 genes derived from antiretroviral therapy-naive individuals residing in Sorong, West Papua. HIV-1 genomic fragments were amplified from 43 peripheral blood samples, and sequencing analysis of the genes was carried out. Of the 43 samples, 41 protease (PR), 31 reverse transcriptase (RT), 26 gag, and 25 env genes were sequenced. HIV-1 subtyping revealed that CRF01_AE (48.8%, 21/43) and subtype B (41.9%, 18/43) were the major subtypes prevalent in the region, whereas other recombinant forms were also detected. Major drug resistance-associated mutations for PR inhibitors were not detected; however, mutations for the RT inhibitors, A62V and E138A, appeared in a few samples, indicating the possible emergence of transmitted HIV-1 drug resistance in Sorong, West Papua.

Kepulauan Riau is a famous tourist destination in Indonesia. The epidemic of human immunodeficiency virus type 1 (HIV-1) infection is gradually increasing in this region. We collected peripheral blood samples from 62 antiretroviral therapy-experienced individuals. The amplification of viral genomic fragments, HIV-1 subtyping, and the detection of HIV drug resistance (HIVDR) were performed. Viral subtyping revealed that the most prevalent HIV-1 subtype/circulating recombinant form (CRF) was CRF01_AE (55.6%), followed by recombinants between CRF01_AE and subtype B (17.8%) and then subtype B (15.6%). Recombinants containing CRF02_AG gene fragments were also detected (11.1%). Regarding HIVDR, no drug resistance-associated major mutations were found in pol genes encoding protease, although minor mutations were frequently detected. Furthermore, major mutations, including M184V (2.2%) and Y188L (2.2%), were identified in the viral pol gene encoding reverse transcriptase derived from a study participant, suggesting that the prevalence of HIVDR is low in the region.