High impact information on Skl tripeptide

• The aim of our studies was to analyze cell lines from six different complementation groups in a systematic manner for the presence of peroxisome ghosts, the ability to import Ser-Lys-Leu-containing proteins into peroxisome ghosts and for the presence of cytosolic factors required for peroxisomal protein import [1].
• To examine the structural requirements for organellar localization, the Ser-Lys-Leu carboxyl-terminal tripeptide, a common motif for localization of peroxisomal proteins, was removed by mutagenesis of the MDH3 gene [2].
• The MDH3 sequence was found to contain a carboxyl-terminal SKL tripeptide, characteristic of many peroxisomal enzymes, and immunochemical analysis was used to confirm organellar localization of the MDH3 isozyme [3].
• Carboxyl-terminal sequences Ser-Lys-Leu (SKL) and Leu-Gln-Ser-Lys-Leu (LQSKL) of acyl-CoA oxidase (AOX) directed to peroxisomes the fused proteins with import-incompetent forms of AOX and catalase that had been truncated, implying that the SKL tripeptide functions as a targeting signal [4].
• They also suggest that the non-consensus PTS1 of human AGT might interact with HsPex5p very differently compared with the consensus PTS1, Ser-Lys-Leu [5].

Biological context of Skl tripeptide

• The open reading frame contains an N-terminal mitochondrial targeting sequence and the C-terminal part of the enzyme ends with a peroxisomal (Ser-Lys-Leu) targeting motif [6].
• The deduced amino acid sequence displays a terminal tripeptide Ser-Lys-Ile which is highly homologous to the PTS (Ser-Lys-Leu) found in other peroxisomal enzymes [7].
• The mutant cells exhibited a temperature-sensitive (TS) phenotype on the peroxisomal localizations of the recombinant GFP and urate oxidase appending a genuine peroxisome targeting signal 1 (PTS1), a tripeptide of Ser-Lys-Leu (SKL) at the C-terminus, but did not on that of catalase harboring a divergent PTS1, Lys-Ala-Asn-Leu (KANL) sequence [8].

Anatomical context of Skl tripeptide

• In contrast to reports of Neurospora crassa, our results demonstrate that A. nidulans contains only one type of microbody (peroxisomes) that carry out the glyoxylate cycle and contain 3-ketoacyl-CoA thiolase and proteins with the C-terminal SKL tripeptide [9].

Gene context of Skl tripeptide

• Although the nucleotide and deduced amino acid sequences of these cDNAs are almost identical, the deduced HPR1 protein contains Ser-Lys-Leu at its carboxy-terminal end, which is known as a microbody-targeting signal, while the deduced HPR2 protein does not [10].
• Rat liver catalase is sorted to peroxisomes by its C-terminal tripeptide Ala-Asn-Leu, not by the internal Ser-Lys-Leu motif [11].
• A synthetic peptide composed of the C-terminal 10 amino acid residues of acyl-CoA oxidase (the C-terminal tripeptide is Ser-Lys-Leu) inhibited the import of urate oxidase, whereas other peptides, in which the C-terminal Ser-Lys-Leu (SKL) sequence was deleted or mutated, were not effective [12].

Analytical, diagnostic and therapeutic context of Skl tripeptide

• This report describes the microinjection of two proteins, (i) luciferase and (ii) albumin conjugated to a peptide ending in the sequence Ser-Lys-Leu, into mammalian cells grown in tissue culture [13].

References