High impact information on PGM5

• In the reverse immunoprecipitation experiments, aciculin was detected in the precipitates with different anti-dystrophin antibodies [1].
• Using immunoprecipitation from cell lysates of metabolically labeled differentiating C2C12 muscle cells with anti-aciculin-specific antibodies, we detected a high molecular weight band (M(r) approximately 400,000), consistently coprecipitating with aciculin [1].
• Association of aciculin with dystrophin (utrophin) in various cell types might provide an additional cytoskeletal-matrix transmembrane link at sites where actin filaments terminate at the plasma membrane [1].
• Immunodepletion experiments with lysates of metabolically labeled C2C12 myotubes showed that aciculin is a major dystrophin-associated protein in cultured skeletal muscle cells [1].
• A novel phosphoglucomutase-related protein is concentrated in adherens junctions of muscle and nonmuscle cells [2].

Biological context of PGM5

• We propose that the PGM-RP gene, which we have mapped to human chromosome 9qcen-q13, evolved from the PGM1 gene, and encodes a protein with a structural rather than an enzymatic role [3].
• The active site consensus sequences of prokaryotic and eukaryotic mutases are not conserved in PGM-RP, a finding consistent with the lack of enzymatic activity of PGM-RP in vitro, and the absence of a phosphorylated intermediate in vivo [3].
• We have sequenced 1.8 kb of the human PGM-RP promoter and shown that it lacks a conventional TATA box [4].
• PGM-RP is therefore a good marker of the contractile/differentiated smooth muscle phenotype [4].

Anatomical context of PGM5

• PGM-RP is expressed predominantly in muscle with the highest levels in smooth muscle [3].
• Rabbit anti-aciculin antibody frequently formed doublets with monoclonal antibodies against the N- or C-terminal domain of dystrophin at the muscle cell surface [5].
• We have recently characterised a 60-kDa muscle-specific phosphoglucomutase-related protein (PGM-RP) which is expressed predominantly in adult visceral and vascular smooth muscle [4].
• Aciculin and its relation to dystrophin: immunocytochemical studies in human normal and Duchenne dystrophy quadriceps muscles [5].
• Aciculin was detected by immunoblotting in antiutrophin immunoprecipitates from A7r5 and REF52 cultured cells, indicating an association between these two proteins [6].

Associations of PGM5 with chemical compounds

• Levels of PGM-RP increased in quiescent PAC1 and A10 cells, and were elevated in response to angiotensin II [4].
• The aciculin-utrophin complex in fibroblasts and smooth muscle cells was mostly resistant to Triton X-100 extraction and was detected predominantly in the Triton-insoluble fraction, enriched in actin and actin-associated proteins [6].

Other interactions of PGM5

• The organisation of the PGM-RP gene is essentially identical to that of PGM1 [3].
• The significance of the interaction between dystrophin/utrophin and an increasing number of cytoplasmic proteins including PGM-RP remains to be explored [3].
• Within these gene duplicates, the number of expressed paralogous loci varies, from one in PGM5 to all three in CBWD and Hs.115173 [7].
• Aciculin is a novel adherens junction antigen extracted from human uterine smooth muscle that is reported to associate biochemically with dystrophin [5].

Analytical, diagnostic and therapeutic context of PGM5

• By immunofluorescence both aciculin and utrophin were identified in a similar dot-like or streak-like pattern in A7r5 and REF52 cultured cells [6].

References