Sir2-Related Protein 1 fromLeishmania amazonensisis a glycosylated NAD⁺-dependent deacetylase

Abstract

Sirtuin proteins form a family of NAD + -dependent protein deacetylases that are considered potential drug targets against parasites. Here, we present the first characterization of a sirtuin orthologue from Leishmania amazonensis, an aetiological agent of American tegumentary leishmaniasis that has been the subject of many studies focused in the development of therapeutic approaches. The protein has high sequence identity with other Kinetoplastid Silent information regulator 2 Related Protein 1 (Sir2RP1) and was named LaSir2RP1. The gene exists as a single copy, encoding a monomeric protein (LaSir2RP1) of approximately 41 kDa that has NAD + -dependent deacetylase activity. LaSir2RP1 was immunodetected in total protein extracts, in cytoplasmic granules, and in the secreted material of both promastigotes and lesion-derived amastigotes. Analysis of both lectin-affinity purified promastigote and amastigote extracts revealed the presence of a major enriched protein of approximately 66 kDa that was recognized by an anti-LaSir2RP1 serum, suggesting that a parasite sirtuin could be glycosylated in vivo.

Lysine Acetylation: Elucidating the Components of an Emerging Global Signaling Pathway in Trypanosomes

“…Leishmania amazonensis Sir2 RP1 is expressed in cytoplasmatic vesicles of both promastigote and amastigote developmental forms. Its secretion/excretion was correlated with the glycosylation state of the protein [85]. Tb SIR2 RP1 is a nuclear and chromosome-associated protein.…”

Silent Information Regulator 2 from Trypanosoma cruzi Is a Potential Target to Infection Control

“…The association with cytoskeleton is a characteristic feature of both SIRT2 and HDAC6 in mammalian cells [32,148]. In addition, an orthologous from L. amazonensis, LaSir2rp1 was found to be a glycosylated protein, but whether this is the case for other species remains to be seen [149]. Although the Sir2 related protein 1 has received much attention, no studies have been made for the other two proteins codified by the Leishmania species; Sir2 related protein 2 and Sir2 related protein 3.…”

Sirtuins of parasitic protozoa: In search of function(s)

“…L. major LmSIR2rp1 physically interacts with a heat shock protein HSP83 (a mammalian orthologue of HSP90), although it does not seem to deacetylate the HSP83 itself [157]. L. amazonensis SIR2rp1 (LaSIR2rp1) exhibits some substrate specificity in that it was able to deacetylate a major acetylated protein (∼50 kDa) in promastigote extracts but not acetylated BSA [158]. LiSIR2rp1 was found principally in the cytoplasm and partially co-localised with the microtubule network, but is reported to be found in cytoplasmic granules and in excreted-secreted antigens (ESA), as is LmSIR2rp1 and LaSIR2rp1 in both promastigotes and amastigotes [158,159].…”

“…LiSIR2rp1 like TbSIR2rp1 and PfSIR2A also auto ADP-ribosylates itself in the presence of histones and exhibits both NAD + -dependent deacetylase activity as well as ADP-ribosyltransferase activity [159,160]. LaSIR2rp1 is a sirtuin-type deacetylase though the ADP-ribosyltransferase activity was not formally shown [158]. LaSIR2rp1 was proposed to be glycosylated in vivo since it was immuno-detected in lectin affinity purified promastigote and amastigote extracts [158].…”

“…LaSIR2rp1 is a sirtuin-type deacetylase though the ADP-ribosyltransferase activity was not formally shown [158]. LaSIR2rp1 was proposed to be glycosylated in vivo since it was immuno-detected in lectin affinity purified promastigote and amastigote extracts [158]. Over-expression of LmSIR2rp1 in different Leishmania species significantly delayed apoptosis-like death at different parasite stages [160].…”