Disease relevance of Rce1

• Contrary to our hypothesis, the inactivation of Rce1 actually increased peripheral leukocytosis, increased the release of immature hematopoietic cells into the circulation and the infiltration of cells into liver and spleen, and caused mice to die more rapidly [1].
• Pathological studies revealed that the heart-specific Rce1 knockout mice had a dilated cardiomyopathy [2].
• Endoproteolytic processing of RhoA by Rce1 is required for the cleavage of RhoA by Yersinia enterocolitica outer protein T [3].

High impact information on Rce1

• We previously showed that inactivation of Rce1 in mouse fibroblasts mislocalizes RAS proteins away from the plasma membrane and inhibits RAS transformation [1].
• Moreover, in the absence of Rce1, splenocytes and bone marrow cells expressing oncogenic K-RAS yielded more and larger colonies when grown in methylcellulose [1].
• Homozygous Rce1 mutant embryos (Rce1(-/-)) die late in gestation [4].
• Rce1(-/-) fetal liver cells rescued lethally irradiated recipients and manifested normal long-term repopulating potential in competitive repopulation assays [4].
• To characterize the role of Rce1 in hematopoiesis, we performed adoptive transfers and investigated cells from the recipients [4].

Biological context of Rce1

• After isoprenylation, Ras and other CAAX proteins undergo endoproteolytic processing by Rce1 and methylation of the isoprenylcysteine by Icmt (isoprenylcysteine carboxyl methyltransferase) [5].
• We reported previously that Rce1-deficient mice died during late gestation or soon after birth [5].
• Contrary to our expectation, Icmt deficiency caused a more severe phenotype than Rce1 deficiency, with virtually all of the knockout embryos (Icmt-/-) dying by mid-gestation [5].
• After isoprenylation, the Ras proteins and other CAAX proteins undergo two additional enzymatic modifications-endoproteolytic release of the last three amino acids of the protein by the protease Rce1 and methylation of the carboxyl-terminal isoprenylcysteine by the methyltransferase Icmt [6].
• Absence of the CAAX endoprotease Rce1: effects on cell growth and transformation [6].

Anatomical context of Rce1

• We generated mice with a conditional Rce1 allele (Rce1(flox)) and produced Rce1(flox/flox) fibroblasts [6].
• The recipients of Rce1(-/-) cells developed modest elevations in mature myeloid cells (neutrophils + monocytes), but remained well [4].
• The excision of Rce1 from a Rce1(flox/flox) skin carcinoma cell line also significantly retarded the growth of cells, and this effect was exaggerated by cotreatment of the cells with a farnesyltransferase inhibitor [6].
• After prenylation, the last three residues of CAAX proteins are clipped off by Rce1, an integral membrane endoprotease of the endoplasmic reticulum [2].
• Finally, membranes from Rce1-deficient fibroblasts lacked the capacity to proteolytically process farnesylated Ha-Ras, N-Ras, and Ki-Ras or geranylgeranylated Ki-Ras [7].

Associations of Rce1 with chemical compounds

• After isoprenylation, the Ras proteins and other proteins terminating with a so-called CAAX motif undergo two additional modifications: (1) endoproteolytic cleavage of the -AAX by Ras converting enzyme 1 (Rce1) and (2) carboxyl methylation of the isoprenylated cysteine residue by isoprenylcysteine carboxyl methyltransferase (Icmt) [8].

Other interactions of Rce1

• We hypothesized that Rce1-deficient mouse fibroblasts, in which the geranylgeranylated Rho proteins are not endoproteolytically processed, would be resistant to YopT [3].

Analytical, diagnostic and therapeutic context of Rce1

• Microinjection of recombinant YopT into Rce1-deficient fibroblasts had no impact on the subcellular localization of RhoA and no impact on cell morphology [3].

References