Disease relevance of Actg1

• Recombinant phages that carry the human smooth muscle (enteric type) gamma-actin gene were isolated from human genomic DNA libraries [1].
• In the present work insulin was found to rapidly, but transiently, increase transcription of the cytoskeletal gamma-actin gene in rat H4IIE (H4) hepatoma cells [2].
• Hypothyroidism was associated with a reduction in the steady state level of beta-actin mRNA during the entire period, but levels of gamma-actin mRNA were reduced only during the early phase of synaptogenesis (first week) [3].

High impact information on Actg1

• Structure, chromosome location, and expression of the human smooth muscle (enteric type) gamma-actin gene: evolution of six human actin genes [1].
• In hypertrophied vessels, alpha-actin decreased (by 15%) and gamma-actin increased (by 20%) [4].
• The rapid localization of beta-actin mRNA, but not gamma-actin mRNA, into processes and growth cones could be induced by dibutyryl cAMP treatment [5].
• By using specific antibodies against the isoforms for tropomyosin (Tm) (Tm-5 and TmBr-1/-3) and actin (beta- and gamma-actin), we found that during early morphogenesis in vivo immature growing axons contain beta- and gamma-actin and Tm-5 [6].
• Cytoplasmic beta- and gamma-actin mRNAs as well as smooth muscle actin mRNAs have been shown to be transiently increased in rat uterus after treatment with the steroid hormone estradiol [7].

Biological context of Actg1

• This suggested that gamma-actin participated in myofibrillogenesis in a manner indistinguishable from that of alpha-actin [8].
• Regulation of gamma-actin gene expression by insulin [2].
• The transcript and protein levels of gamma-actin were increased significantly in the second part of gestation (31.8-fold increase for mRNA and 16.7-fold increase for protein relative to nonpregnant) [9].
• In young cerebellar cultures, gamma-actin is found in the cell body, neurites and growth cones, while beta-actin is mainly found in growth cones, as previously reported in other primary neuronal culture systems [Kaech et al. (1997), J. Neuroscience, 17, 9565-9572; Bassell et al., (1998), J. Neuroscience, 18, 251-265] [10].
• The expression of smooth muscle alpha-actin (Acta2, which we abbreviate as alpha-SM-actin) and gamma-actin mRNAs and proteins was examined by real-time polymerase chain reaction and Western immunoblot, and was localized with immunohistochemistry, in the nonpregnant, pregnant, and postpartum rat uterus [9].

Anatomical context of Actg1

• To this list we add osteoblasts, in which we show by in situ hybridization that beta-actin is distributed primarily in cell processes and on one side of the nucleus and gamma-actin has a perinuclear distribution [11].
• Titin assembly on the SFLS often appeared prior to the onset of either alpha- or gamma-actin periodicity on nascent myofibrils; the latter result suggested a role for titin in sarcomeric organization [8].
• The temporal alteration in gamma-actin expression and localization at late gestation suggested that this change in myometrial composition of contractile proteins is important to adequately prepare the myometrium for the development of optimal contractions during labor [9].
• Gamma-actin protein translocated to the membranous region of uterine myocytes at late gestation [9].
• Electron microscopy of post-embedding immunogold-labelled tissue confirms the widespread distribution of gamma-actin, and also reveals an increased concentration of gamma-actin in dendritic spines in the adult [10].

Associations of Actg1 with chemical compounds

• Glucose stimulated the steady state of c-myc mRNA transcripts in a dose-responsive manner without any change of gamma-actin mRNA levels after 2 h of treatment [12].
• The cDNAs which were specific for beta and gamma actin isoforms yielded hybridization signals in extracts from CMC exposed to 10(-7) M and 10(-6) M ADR [13].
• Corticosterone administration, which is known to impair the reinnervation process in ECL rats, prevents the lesion-induced reduction in gamma-actin expression and blocks the induction of alpha 1-tubulin in the deafferented hippocampus [14].
• Regulation of beta- and gamma-actin mRNA by thyroid hormone in the developing rat brain [3].
• In polypeptides extracted in the Triton X-100-soluble pool, the effect on CMC alpha-actin synthesis was greater than the effect on beta- or gamma-actin [15].

Regulatory relationships of Actg1

• The rats of transcription of both beta- and gamma-actin mRNAs were stimulated by T3 during the early phase but that of beta-actin mRNAs was relatively more sensitive to T3 than gamma-actin mRNA [3].

Other interactions of Actg1

• In situ hybridization studies showed greater beta-actin mRNA levels but no change in gamma-actin mRNA levels-suggesting that axon regrowth utilizes beta-actin [16].
• Allografts were removed, mRNA isolated, and Northern blotting or RT-PCR performed with blots probed with cDNAs or oligos specific for rat TNF-alpha cyclophylin and gamma-actin [17].
• Insulin-induced transcription of the gamma-actin gene was evident within 5 min and was maximal by 15 min at 10-fold above control levels [2].
• Cyclical stretch of randomly cycling cells, seeded on a flexible elastin substrate at a rate of 100 cycles/min for 72 h, did not significantly influence the pattern of alpha-SM or beta/gamma-actin mRNA expression in neo-LF-1 or ras-LF-1 cells [18].
• Coimmunofluorescence studies with MAP-2 and gamma-actin revealed that at P12, AMF-R was mainly localized to Purkinje and granule cells [19].

Analytical, diagnostic and therapeutic context of Actg1

• Immunogold electron microscopy in normal rat kidney cells revealed that beta- and gamma-actin isoforms were found in Golgi-associated COPI-coated buds and vesicles [20].
• Northern blot analysis using cDNA probes for TRPM-2 and gamma-actin were performed at each time point [21].
• The newly developed DNA biosensors have been used for the precise quantification of a specific rat gamma-actin mRNA sequence amplified by the polymerase chain reaction [22].
• 2-D Western blot analyses for randomly selected proteins (ezrin, HSP70, beta- and gamma-actin, Rho-GDI, and l-myc) clearly confirmed the proteomic identification [23].
• When polysomal RNA was separated by sucrose gradient centrifugation, both beta- and gamma-actin mRNAs appeared as a sharp peak at the region slightly heavier than 18 S RNA [24].

References