Disease relevance of Pcp2

• We produced eight recombinant replication-defective adenoviruses carrying the lacZ reporter gene driven by various promoters, including those of the L7/PCP2 gene (highly restricted expression in cerebellar Purkinje cells), and the myelin basic protein (in oligodendrocytes) gene [1].
• Immune responses of mice to vaccinia virus recombinants expressing either Listeria monocytogenes partial listeriolysin or Brucella abortus ribosomal L7/L12 protein [2].

High impact information on Pcp2

• Expression of the transgene in adult reeler mutant mice, which show inverted cortical lamination, and in primary culture showed that the initial expression of L7 is intrinsic to Purkinje cells and does not depend on extracellular signals [3].
• A genomic clone encoding the Purkinje cell-specific L7 protein has been isolated and utilized to drive the expression of beta-galactosidase in mice [4].
• Three independent transgenic lines, germ line transformed with an L7-beta-galactosidase fusion gene, exhibit beta-galactosidase expression in both cerebellar Purkinje cells and retinal bipolar neurons [4].
• Purkinje cell protein-2 regulatory regions and transgene expression in cerebellar compartments [5].
• Whereas the absolute gain, phase, and latency values of the vestibulo-ocular reflex and optokinetic reflex of the L7-PKCI mice were normal, their ability to adapt their vestibulo-ocular reflex gain during visuo-vestibular training was absent [6].

Biological context of Pcp2

• Previous studies showed that mice carrying a Cre transgene produced by insertion of Cre cDNA into a small 2.88-kb Pcp2 DNA fragment expressed Cre in Purkinje cells; however, some Cre activity was also observed outside the target tissues [7].
• L7/Pcp-2 is a GoLoco domain protein that modulates the activation of Galpha(i) and Galpha(o) [8].
• These data, combined with evidence that the tissue distribution of rho1 and L7 RNA in the CNS are similar, indicates that rho1 and L7 may share common transcriptional regulatory elements [9].
• In contrast, another homeodomain protein that is normally expressed in Purkinje cells only during the embryonic period, En-2, has a negative effect on L7 gene expression [10].
• METHODS: The IRES-Cre-cDNA fragment was inserted into a 173-kb bacterial artificial chromosome (BAC) carrying the intact Pcp2 gene, by using red-mediated recombineering [11].

Anatomical context of Pcp2

• In addition, when Galphao and Pcp2 were cotransfected into COS cells, Galphao was detected in immunoprecipitates of Pcp2 [12].
• Further, immunofluorescent double labeling and confocal microscopy suggest that Pcp2 and Galpha(o) are colocalized in the distal processes of cerebellar Purkinje cells including axonal endings and dendritic spines [13].
• Purkinje cell protein 2 (Pcp2/L7) expression is highly restricted to Purkinje and retinal bipolar cells, where it has been exploited to enable highly specific, Cre recombinase-mediated, site-specific recombination [7].
• While the function of L7/pcp-2 is unknown, its mRNA is trafficked into dendrites, suggesting a role in dendritic physiology [14].
• The L7 mRNA was abundant, stable (t1/2 > 10 h), and polyadenylated in presenescent and senescent human fibroblasts; however, steady state mRNA levels were 5-10-fold lower in senescent cells, whether derived from fetal lung or neonatal foreskin [15].

Associations of Pcp2 with chemical compounds

• Galphao and Pcp2 binding was confirmed in vitro using glutathione S-transferase-Pcp2 fusion proteins and in vitro translated [35S]methionine-labeled Galphao [12].
• Developmentally regulated expression of GABA receptor rho1 and rho2 subunits, L7 and cone-rod homeobox (CRX) genes in mouse retina [9].
• Therefore, we have initiated the following series of studies to define more precisely the location of the thyroid hormone regulatory elements in the Pcp-2 gene [16].
• Moreover, we also show that there is a correlation between the M-L clusters established by the birth date-related Purkinje cells and the domains of engrailed-2, Wnt-7B, L7/pcp2, and EphA4 receptor tyrosine kinase expression [17].
• This differential expression was not seen from P7 to adulthood, and the parasagittal pattern until P5 was different from those of L7, zebrins, and the integrin beta1 subunit [18].

Regulatory relationships of Pcp2

• Transient expression study demonstrated that transcription of the Purkinje cell protein-2 (Pcp-2) gene is activated by ROR alpha, which binds as a monomer to a single half-site motif (RORE) within the promoter region [19].

Other interactions of Pcp2

• Northern analysis of total mRNA from the brains of wild-type mice established that, as in the rat pup, the initial rate of rise of the MBP and Pcp-2 mRNA is slowed in the hypothyroid state [20].
• To elucidate the roles of individual Src family members in vivo, we generated transgenic mice expressing the neuronal form of c-Src (n-Src), Fyn, and their constitutively active forms in cerebellar Purkinje cells using the L7 promoter [21].
• The fundamental organization of Purkinje cell sagittal zones as revealed by the "early onset" markers L7-beta-gal and cadherin-8 was found to be virtually identical to that in wild type [22].
• Pcp2 is uniquely expressed in cerebellar Purkinje cells and in retinal bipolar neurons, and it may function as a cell-type specific modulator for G protein-mediated cell signaling [13].
• To evaluate whether the two proteins caused cerebellar neurodegeneration by the same mechanism, we generated transgenic mice selectively expressing Dpl in Purkinje cells by the same L7 promoter [23].

Analytical, diagnostic and therapeutic context of Pcp2

• The different temporal patterns were confirmed by co-amplification of rho1, rho2, and L7 in a single PCR tube [9].
• This distribution is the same as that previously determined for the L7 protein by immunohistochemistry [4].
• In addition, the compensatory eye movements of L7-PKCI mice were recorded during vestibular and visual stimulation [6].
• The level of GFP expression can be quantified by western blotting which allows to analyze protein expression and L7/pcp-2 promoter regulation in vivo [24].
• Gel shift analysis reveals that nuclear proteins from fetal but not adult brains complex with the -267/ -199 region, supporting the hypothesis that this region binds proteins that suppress Pcp-2 expression early in brain development [25].

References