Title : Coding of two sphingolipid activator
proteins (
SAP-1 and
SAP-2 ) by same genetic locus
Abstract :
- Several complementary DNAs (cDNAs) coding for sphingolipid activator protein-2 ( SAP-2 ) were isolated from a lambda gt-11 human hepatoma library by means of polyclonal antibodies
- The nucleotide sequence of the largest cDNA was colinear with the derived amino acid sequence of SAP-2 and with the nucleotide sequence of the cDNA coding for the 70-kilodalton precursor of SAP-1 ( SAP precursor cDNA )
- The coding sequence for mature SAP-2 was located 3' to that coding for SAP-1 in the SAP precursor cDNA
- Both SAP-1 and SAP-2 appeared to be derived by proteolytic processing from a common precursor that is coded by a genetic locus on human chromosome 10
- Two other domains similar to SAP-1 and SAP-2 were also identified in SAP precursor protein
- Each of the four domains was approximately 80 amino acid residues long, had nearly identical placement of cysteine residues , potential glycosylation sites, and proline residues
- Each domain also contained internal amino acid sequences capable of forming amphipathic helices separated by helix breakers to give a cylindrical hydrophobic domain that is probably stabilized by disulfide bridges
- Protein immunoblotting experiments indicated that SAP precursor protein (70 kilodaltons) as well as immunoreactive SAP-like proteins of intermediate sizes (65, 50, and 31 kilodaltons) are present in most human tissues
Output (sent_index, trigger,
protein,
sugar,
site):
- 6. glycosylation, , -, -, sites, and proline residues
Output(Part-Of) (sent_index,
protein,
site):
- 2. SAP-2, sequence
- 7. -, sequences
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):