High impact information on Atp2a3

• We investigated the expression of the SERCA2 and SERCA3 isozymes in PC12 cells exposed to agents interfering with different aspects of the posttranslational protein processing within the ER, thereby activating the ER stress-induced unfolded protein response (UPR) [1].
• Its identification using 3'-end SERCA3 gene and rapid amplification of cDNA ends (RACE)-PCR studies showed that it results from an additional SERCA3 alternative splicing process, which uses a second alternative polyadenylation site located in the last intron [2].
• SERCA1b, SERCA2b and SERCA3 mRNA levels fell below the detection limit in the diaphragm of both control and triamcinolone-treated rats [3].
• Chronic activation of insulin receptor signaling by IRS-1 overexpression in the beta-cell inhibited gene expression of SERCA3, an endoplasmic reticulum Ca(2+)-ATPase [4].
• This study identifies a novel regulatory pathway of insulin secretion at the molecular level with two main components: (1) regulation of intracellular Ca(2+) homeostasis via SERCA3 and (2) regulation of insulin gene expression [4].

Biological context of Atp2a3

• The SERCA3 resistance to oxidants may aid the cells expressing it to function during exposure to oxidative stress [5].
• However, for microsomes from SERCA3-expressing cells, the corresponding values of IC50 for peroxide were 274 +/- 47, 857 +/- 110, and 746 +/- 40 microM [5].
• Thus, beta-cell SERCA3 is a target for insulin regulation, which implies that beta-cell Ca(2+) homeostasis is regulated in an autocrine feedback loop by insulin [4].
• We demonstrate that early in embryogenesis, SERCA 3 mRNA is highly expressed in the heart tube and is also present in the yolk sac [6].

Anatomical context of Atp2a3

• We found, using RT-PCR with isoform-specific primers, that SERCA 2 and SERCA 3 mRNAs are co-expressed in human and rat islets of Langerhans and in the RINm5F beta-cell line [7].
• We report the distribution of the sarco(endo)plasmic reticulum Ca2+ ATPase 3 (SERCA3) isoform in the rat brain [8].
• SERCA3 expression is very low or absent in the rat cerebrum and brainstem [8].
• It is known that the SERCA3 Ca2+ pump has an approximately 5-fold lower affinity for Ca2+ when expressed in COS cells as compared to other SERCA members [15] [8].
• Endothelium from rat aorta expresses sarco/endoplasmic reticulum Ca2+(SERCA) pump gene SERCA3 where as the smooth muscle expresses SERCA2 [9].

Associations of Atp2a3 with chemical compounds

• Treatment with thapsigargin (Tg) or A-23187 increased the level of mRNA encoding SERCA2b four- to fivefold; SERCA3 increased about 10-fold, whereas SERCA2a was unchanged [10].

Other interactions of Atp2a3

• Sarco(endo)plasmic reticulum Ca2+ pumps are encoded by genes SERCA1, SERCA2, and SERCA3 [5].

Analytical, diagnostic and therapeutic context of Atp2a3

• For SERCAs, comparative analyses of human and Wistar-Kyoto rat SERCA3 platelet mRNA by reverse transcription-polymerase chain reaction (RT-PCR) followed by sequencing established that human platelets coexpressed SERCA3b and a third SERCA3c, while rat cells were devoid of them but expressed a still unknown splice variant that we termed rSERCA3b/3c [2].
• Immunocytochemistry clearly revealed the expression of SERCA3 in the cell body and in the dentritic processes of the Purkinje neurons [8].
• We have used in situ hybridization and RNase protection techniques to demonstrate that SERCA 3 mRNA is expressed in specific cell types, namely the endothelial and epithelial cells [11].
• On the other hand, SERCA3 mRNA was not detected in thyroid by Northern blot analysis, or barely detected by RT-PCR assays [12].

References