Alternative titles; symbolsLONG-TERM SYNAPTIC FACILITATION PROTEIN LLPHHGNC Approved Gene Symbol: LLPHCytogenetic location: 12q14.3 Genomic coordinates (GRCh...
Alternative titles; symbols
HGNC Approved Gene Symbol: LLPH
Cytogenetic location: 12q14.3 Genomic coordinates (GRCh38): 12:66,116,554-66,130,749 (from NCBI)
LLPH is an intrinsically disordered protein predicted to function in nucleolus, possibly as a molecular hub for protein-protein interactions (Yu et al., 2016).
▼ Cloning and Expression
Yu et al. (2016) cloned mouse Llph, which they called Llp, and identified orthologs in human, other vertebrates, and C. elegans. The deduced mouse and human proteins contain 130 and 129 amino acids, respectively, and both have polybasic N- and C-terminal nuclear localization sequences. Western blot analysis detected high Llp expression in mouse spleen, testis, kidney, liver, and lung, with lower expression in hippocampus, cortex, cerebellum, and heart. Llp was more highly expressed early in mouse development, with a sharp decline until adulthood. In cultured primary mouse hippocampal neurons, Llp expression was high in earlier culture stages and declined with dendritic growth. Fluorescence-tagged mouse Llp localized to nucleus in mouse hippocampal neurons and showed colocalization with a nucleolar marker.
▼ Gene Function
Yu et al. (2016) found that application of mouse Llp to culture medium of HEK293T cells or mouse hippocampal neurons resulted in Llp internalization and nuclear localization. In hippocampal neurons, administration of Llp enhanced dendritic growth and arborization and elevated miniature excitatory postsynaptic current density. Knockdown of Llp in neurons had the opposite effects. Mass spectrometric analysis of proteins that immunoprecipitated with Llp from NIH3T3 nuclear lysates identified nuclear myosin I-beta (MYO1C; 606538) and the transcription factor Ctcf (604167), suggesting that Llp may have a role in transcriptional regulation.
Hartz (2016) mapped the LLPH gene to chromosome 12q14.3 based on an alignment of the LLPH sequence (GenBank BC006002) with the genomic sequence (GRCh38).