High impact information on CPLX2

• The cpx1 gene encodes the expected plastid transit peptide, but this region is deleted from the cpx2 gene [1].
• While the 5' regions of both messenger RNAs are highly similar, the cpx2 gene has an open-reading frame that could encode a new targeting signal [1].
• In contrast, the GFP fusion with CPX2 did not target plastids and appeared to localize to mitochondria [1].
• The cpx1 and cpx2 genes of maize are a singular example of duplicated genes that have diverged by deletion and creation of protein targeting information [1].
• Exon A is localized within CPLX2 intron 2 about 7 kb upstream to exon III [2].

Biological context of CPLX2

• In silico data suggest that two putative alternative TATA-less promoter regions separated by 74 kb govern the expression of two CPLX2 transcripts [2].
• Several potential transcription start sites were detected by primer extension for each of two alternative CPLX2 transcripts [2].
• RESULTS: Although there was no significant difference in the genotypic distributions and allelic frequencies of either SYN2 or CPLX2 polymorphisms between the schizophrenia and control groups, the two-way haplotype analyses revealed significant associations with the disease (P < 0.05 after Bonferroni correction) [3].
• METHODS: Six single nucleotide polymorphisms (SNPs) and one 5-bp insertion/deletion in SYN2 and five SNPs in CPLX2 were genotyped in 154 Korean patients with schizophrenia and 133 control patients using direct sequencing or restriction fragment length polymorphism analysis [3].

Anatomical context of CPLX2

• These results suggest that the two isoforms of synaphin are involved in synaptic function at the distinct presynaptic regions in the central nervous system, and that some dendrites are another functional site for the proteins [4].
• Synaphin is a 19,000 mol. wt cytosolic protein we first found to co-purify with the docking/fusion complex crucial to neurotransmitter release from presynaptic terminals [5].
• In some regions, including the caudate-putamen, globus pallidus, pontine reticular nucleus, cerebellar nuclei and spinal gray matter, synaphin 1 was mainly present in small or medium-sized neurons, while synaphin 2 was in large cells [4].

Physical interactions of CPLX2

• Phosphorylated synaphin/complexin found in the brain exhibits enhanced SNARE complex binding [6].

Other interactions of CPLX2

• Immunoblotting for synaptic proteins revealed a reduction in complexin 2, which was marked in some grade 1 HD cases and significantly reduced in all late stage cases [7].
• Ten and eleven haplotype-tagging (ht)SNPs in CPLX1 and CPLX2, respectively, were selected [8].
• Like AEBP1 and CPX-2, CPX-1 contains an N-terminal region of 160 amino acids with sequence similarity to the discoidin domain of a variety of proteins [9].
• Identification of mouse CPX-1, a novel member of the metallocarboxypeptidase gene family with highest similarity to CPX-2 [9].

Analytical, diagnostic and therapeutic context of CPLX2

• Only one htSNP (rs930047 in CPLX2) in allele-wise analysis showed significance, and even this disappeared with an increased sample size (563 cases and 519 controls: P = .757) [8].
• After 3 months, CPX 2 was performed and patients changed groups (crossover design); CPX 3 was performed after 3 additional months [10].
• The cellular and subcellular localization of the two synaphin isoforms, proteins associated with the docking/fusion complex crucial to neurotransmitter release, was studied in the rat central nervous system by using light microscopic and electron microscopic immunohistochemistry with monoclonal antibodies specific to each isoform [4].

References