Publikationsdatenbank

Characterization of the self-palmitoylation activity of the transport protein particle component Bet3 (2010)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Kümmel, Daniel

Walter, Julia

Heck, Martin

Heinemann, Udo

Veit, Michael

Quelle

Cellular and molecular life sciences : CMLS

Bandzählung: 67

Heftzählung: 15

Seiten: 2653 – 2664

ISSN: 1420-682x

Sprache

Englisch

Verweise

DOI: 10.1007/s00018-010-0358-y

Pubmed: 20372964

Kontakt

Institut für Immunologie

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51834
immunologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Bet3, a transport protein particle component involved in vesicular trafficking, contains a hydrophobic tunnel occupied by a fatty acid linked to cysteine 68. We reported that Bet3 has a unique self-palmitoylating activity. Here we show that mutation of arginine 67 reduced self-palmitoylation of Bet3, but the effect was compensated by increasing the pH. Thus, arginine helps to deprotonate cysteine such that it could function as a nucleophile in the acylation reaction which is supported by the structural analysis of non-acylated Bet3. Using fluorescence spectroscopy we show that long-chain acyl-CoAs bind with micromolar affinity to Bet3, whereas shorter-chain acyl-CoAs do not interact. Mutants with a deleted acylation site or a blocked tunnel bind to Pal-CoA, only the latter with slightly reduced affinity. Bet3 contains three binding sites for Pal-CoA, but their number was reduced to two in the mutant with an obstructed tunnel, indicating that Bet3 contains binding sites on its surface.