High impact information on Lxn

• Peptides were obtained by partial proteolysis of purified TCI, a protein of approximately 30 kDa, and starting from their sequences, a full-length cDNA encoding a 223-amino acid protein containing three potential phosphorylation sites was cloned from a cDNA library [1].
• The widespread expression of TCI in a number of tissues (e.g., brain, lung, or digestive tract) and its apparently cytosolic localization point to a rather general functional role, e.g., in the control of cytosolic protein degradation [1].
• Neurons expressing latexin, a carboxypeptidase A inhibitor, are restricted to lateral areas in the cerebral cortex of adult and early postnatal rats [2].
• While a substantial fraction of early progenitor cells derived from the lateral cerebral wall became latexin-expressing neurons in both systems, far fewer progenitors from dorsal cortex did so under the same environmental conditions, indicating early establishment of cortical regional specification at the progenitor cell level [2].
• In contrast, tracer injections involving the thalamus, striatum, or contralateral SII and Vi exclusively labeled latexin-nonexpressing neurons in both the SII and Vi [3].

Biological context of Lxn

• The overall density, laminar or sublaminar localization, and cell size distribution of latexin-positive neurons differed substantially across cytoarchitectonic areas within lateral cortex [4].
• These findings suggest that latexin plays a role in regional specification and/or morphogenesis of the forebrain, especially of its dorsal midline structures including the pineal gland [5].
• In the present study, we performed clonal analysis of embryonic cortical neurons in vitro using latexin as a subtype-specific molecular marker of glutamatergic neurons to address whether certain precursors in early cortical anlage are already committed to a single molecular phenotype [6].

Anatomical context of Lxn

• To study the molecular details of the protein, we isolated four independent cDNA clones for latexin from cDNA libraries of the rat cerebral cortex and whole brain using the amino acid sequences of latexin fragments [7].
• These results indicate that latexin is a novel class of neuronal protein which represents intracortical regionality, and suggest that the regional specification of the neocortex involves selective parcellation of neurons which express a particular gene [7].
• In the present study we examined the expression and subcellular localization of latexin in rat peritoneal mast cells [8].
• These results show that latexin is synthesized in rat peritoneal mast cells and suggest that it is associated with a unique type of intracellular granules distinct from MCCPA- and histamine-containing secretory granules and lysosomes [8].
• 1.5 T MR imaging performed 2 months after spinal cord hemisection and SC bridging transplantation is sensitive in detecting low-intensity regenerative tissue cables, and (2). the TCI strongly correlates with the extent of axonal regeneration into implanted SC-seeded guidance channels [9].

Associations of Lxn with chemical compounds

• The latexin-associated granules were separated from MCCPA- or histamine-containing granules on a self-generating density gradient of polyvinylpyrrolidone-coated silica-gel particles (Percoll) [8].
• MCCPA and histamine were released from the mast cells after non-immunological and immunological stimulation with compound 48/80, A23187 and anti-IgE antibody, whereas latexin was not released [8].
• Treatments with high ionic strength and heparinase released latexin from the granules, suggesting that latexin is non-covalently associated with a heparin-like component of the granules [8].
• Five minutes later, they were administered either saline or proven antidotes to cocaine (diltiazem, nicardipine, enzyme converting inhibitor [ECI], enalaprilat associated with diazepam) [10].
• The vast majority of latexin-positive neurons were glutamate-immunoreactive in the six lateral neocortical areas examined, while neurons immunoreactive for both latexin and GABA were virtually absent [4].

Regulatory relationships of Lxn

• In the present study, we first demonstrate in the adult rat that the orphan nuclear receptor Nurr1 is coexpressed in latexin-expressing neurons located in layer V, sublayer VIa, and the white matter of the lateral sector of the neocortex, and also in latexin-negative early born neurons in sublayer VIb of the entire neocortex [11].

Other interactions of Lxn

• Restricted expression of latexin in dorsal midline cells of developing rat forebrain [5].

Analytical, diagnostic and therapeutic context of Lxn

• Western and Northern blots demonstrated that the latexin and its mRNA were expressed predominantly in neural tissues with some expression in non-neural tissues [7].
• In situ hybridization showed that latexin mRNA is synthesized in a subset of neurons in the lateral but not the dorsal neocortex, and that the distribution profile of these neurons is quite similar to that of neurons expressing latexin [7].
• Immunoelectron microscopy revealed that latexin was associated with a minority population of granules [8].
• Immunocytochemically, latexin immunofluorescence was localized on granular structures distinct from MCCPA-, histamine- or cathepsin D-immunopositive granules [8].
• Western blot and reverse-transcriptase-mediated PCR analyses showed that latexin was contained and expressed in the rat peritoneal mast cells [8].

References