ABSTRACT
Familial hypercholesterolemia (FH) is a genetic disease mainly caused by mutations in the low density lipoprotein receptor (LDL-R) gene. However, FH-like phenotypes may also arise from mutations occurring in other genes, the products of which normally interact with the LDL receptor. Although several FH-associated proteins have been discovered, many FH-like phenotypes cannot be linked to mutations in already characterized genes, suggesting the existence of other genes still to be identified, the mutations of which may be directly linked to the FH disorder. In order to identify new putative LDLr interactors possibly involved in its internalization and/or sorting, the cytoplasmic tail of the receptor was used as 'bait' in a two-hybrid assay. We identified an 85-amino acid protein able to bind the LDLr intracellular domain through the last 14 C-terminal amino acids. The novel protein is probably derived from the translation of an alternative open reading frame of the human MT2A gene.
ABSTRACT
In this study, by using different techniques (i.e. Northern blot hybridization, RT-PCR and Southern blot hybridization) on various normal rat tissues, we were able to identify liver, kidney, heart, small intestine, brain, spleen, stomach and prostate as tissues in which the ApoH gene is transcribed. Moreover, for some of these tissues, by in situ hybridization, we found a specific localization of apoH transcripts. For instance epithelial cells of the bile ducts in liver and of the proximal tubules in kidney are the major sites of apoH synthesis. Our data suggest that some of the different physiological roles proposed for apoH could correlate with its direct expression, while others could correlate with its absorption from bloodstream or adjacent cells.
Subject(s)
Gene Expression Profiling/methods , Glycoproteins/metabolism , In Situ Hybridization/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Animals , Cells, Cultured , Humans , Jejunum/metabolism , Kidney/metabolism , Liver/metabolism , Myocardium/metabolism , RNA, Messenger/metabolism , Rats , Rats, Wistar , Tissue Distribution , beta 2-Glycoprotein IABSTRACT
In a previous paper we demonstrated that, in Paracentrotus lividus embryos, deciliation represents a specific kind of stress that induces an increase in the levels of an acidic protein of about 40 kD (p40). Here we report that deciliation also induces an increase in Hsp40 chaperone levels and enhancement of its ectodermal localization. We suggest that Hsp40 might play a chaperoning role in cilia regeneration.
