Disease relevance of Atp1b2

• Expression of adhesion molecule on glia (AMOG) is downregulated in human and mouse gliomas, suggesting that AMOG may be important for growth regulation in the brain [1].

High impact information on Atp1b2

• We generated mice, null mutant in the adhesion molecule on glia (AMOG), the beta 2 subunit of the murine Na,K-ATPase gene [2].
• We hypothesize that AMOG or variants of the beta subunit of the Na,K-ATPase, tightly associated with an alpha subunit, are recognition elements for adhesion that subsequently link cell adhesion with ion transport [3].
• The monoclonal AMOG antibody that blocks adhesion was shown to interact with Na,K-ATPase in intact cultured astrocytes by its ability to increase ouabain-inhibitable 86Rb+ uptake [3].
• AMOG-mediated adhesion occurred, however, both at 4 degrees C and in the presence of ouabain, an inhibitor of the Na,K-ATPase [3].
• Immunoaffinity-purified AMOG was associated with a protein of 100,000 Mr. Monoclonal antibodies revealed that this associated protein comprised the alpha 2 (and possibly alpha 3) isoforms of the Na,K-ATPase catalytic subunit, but not alpha 1 [3].

Biological context of Atp1b2

• Assignment of Amog (adhesion molecule on glia) gene to mouse chromosome 11 near Zfp-3 and Asgr-1,2 and to human chromosome 17 [4].
• We have mapped the AMOG gene to human chromosome 17 and mouse chromosome 11 by somatic cell hybrid analysis [4].
• We show that AMOG does not negatively regulate cell growth in vitro or in vivo [1].
• In this report, we examined the role of AMOG expression on cell growth and intracellular signal transduction [1].
• Apoptotic cell death of photoreceptor cells in mice deficient for the adhesion molecule on glia (AMOG, the beta 2- subunit of the Na, K-ATPase) [5].

Anatomical context of Atp1b2

• In situ AMOG is expressed in the cerebellum by glial cells at the critical developmental stages of granule neuron migration [6].
• One rat and four human glioma cell lines showed complete loss of AMOG [7].
• Functional characterization of beta isoforms of murine Na,K-ATPase. The adhesion molecule on glia (AMOG/beta 2), but not beta 1, promotes neurite outgrowth [8].
• The adhesion molecule on glia (AMOG/beta 2) and alpha 1 subunits assemble to functional sodium pumps in Xenopus oocytes [9].
• Production and secretion in CHO cells of the extracellular domain of AMOG/beta 2, a type-II membrane protein [10].

Associations of Atp1b2 with chemical compounds

• AMOG is an integral cell surface glycoprotein of 45-50-kD molecular weight with a carbohydrate content of at least 30% [6].
• Immunoprecipitation of alpha 1/AMOG complexes from digitonin extracts of [35S]methionine-labeled oocytes with a monoclonal anti-AMOG antibody provides direct evidence for a stable association between AMOG and the alpha 1 subunits of Xenopus and Torpedo [9].

Other interactions of Atp1b2

• In the adult olfactory system, however, a significant retention of CAMs characteristic for developmental and morphogenetic processes, such as E-N-CAM, AMOG, as well as the high molecular weight components of J1 glycoproteins, can be observed [11].
• Our observations demonstrate that the pathological death of cells induced by disruption of the AMOG/beta 2 gene results from activation of an intrinsic death program, similar to what has been shown to occur during normal development [5].

Analytical, diagnostic and therapeutic context of Atp1b2

• Moreover, the proportion of white, type IIb fibers in the mouse and rat muscle samples, as indicated by real-time PCR quantification of Atp1b2 mRNA, showed a strong positive correlation with the expression of gamma3 [12].
• Of all tissues tested, only brain expresses detectable levels of AMOG by ELISA and Northern blot analyses, indicating a high correlation in expression at the protein and mRNA levels [13].
• These findings indicate that AMOG/beta 2 is not necessary for long-term survival of telencephalic graft tissue [14].
• Graft-borne astrocytes express neither the AMOG/beta 1 nor the AMOG/beta 2 subunit of Na,K-ATPase as examined with immunocytochemistry and in situ hybridization [14].
• In the present study, we have identified the oligosaccharides released by endoglycosidase H from the cell adhesion molecules AMOG and L1 by fast-atom bombardment mass spectrometry as being solely of the oligomannosidic type [15].

References