the invention are involved in purine pyrimidine synthesis dna rna synthesis rna processing or amino acid metabolism and protein synthesis 8 different proteins three of the identified proteins 5 aminoimidazole 4 carboxamide ribonucleotide formyltranferase ump cmp kinase and adenine phosphoribosyltransferase involved in the synthesis of purine and pyrimidine were down regulated after exposure to il 1 u03b2 heterogeneous nuclear ribonucleoprotein a2 1311 and m4 protein deletion mutant heterogeneous nuclear ribonucleoprotein m are both involved in processing of prerna 33 34 and were both down regulated too aspartate aminotransferase both the cytosolic and the mitochondrial form involved in amino add metabolism were down regulated after exposure to il 1 u03b2 the down regulation of all these proteins support that the u03b2 cells focus their efforts in protecting themselves against the deleterious effects of il 1 u03b2 and down regulate functions that are not involved in protection endoplasmin one of two proteins in a down regulated spot belongs to the hsp 90 family which is involved in protein folding 38 and has been shown to have serine kinase activity which is enhanced by association with 78 kda glucose regulated protein grp78 39 grp78 was found in three spots one up regulated one down regulated and together with endoplasmin in one down regulated spot demonstrating complex differential regulation of post anslational modifications it is a member of the hsp 70 family involved in the folding and assembly of proteins in the endoplasmatic reticulum 40 endoplasmic reticulum protein erp 29 is a member of the er protein processing machinery and is involved in protein secretory events il 1 u03b2 exposure down regulates this protein protein disulfide isomerase involved in molecular chaperone of glycoprotein biosynthesis 41 is down regulated by.