Cloning and sequencing of rat liver carboxylesterase ES-4 (microsomal palmitoyl-CoA hydrolase).

A cDNA which encodes a carboxylesterase of 561 amino acid residues including a cleavable signal peptide is described. The enzyme expressed in COS cells migrates during PAGE (SDS-, and non-denaturing) as a single prominent band in the region of liver ES-4. It ends in the C-terminal cell-retention signal -HNEL, which, in COS cells overexpressing the enzyme, appears to be slightly less efficient than the signals -HTEL and -HVEL of ES-3 and ES-10 respectively.

The tumor protein MAGE-1 is located in the cytosol of human melanoma cells.

The MAGE-1 protein has been localized to the cytosol of human melanoma culture cells (MZ2-MEL.43) by subcellular fractionation. Its distribution between nuclear, mitochondrial, microsomal and cytosolic fractions was established by SDS-PAGE and immunoblotting with a rabbit antiserum and compared to that of markers for the main cell compartments.

Cloning and sequencing of rat liver carboxylesterase ES-3 (egasyn).

The cDNA of the rat carboxylesterase ES-3 encodes a polypeptide with 561 amino acid residues including a cleavable signal peptide at the N-terminus. The processed polypeptide shows over 90% sequence identity to mouse egasyn (ES-22); its calculated pI (5.5) matches the value determined for purified liver ES-3.

Identification and characterization of the tumor-specific P1A gene product.

In murine mastocytoma P815, gene P1A directs the expression of antigens P815A and B which are the target of a T cell-mediated rejection response in syngeneic animals. This gene is expressed at a high level in various tumors, but is silent in normal tissues except testis and placenta; its activation is thus possibly related to malignant transformation. An anti-synthetic peptide rabbit antiserum reacted by immunoblotting with a cellular protein migrating near 40 kDa on SDS-PAGE.