The Leishmania infantum cytosolic SIR2-related protein 1 (LiSIR2RP1) is an NAD(+)-dependent deacetylase and ADP-ribosyltransferase

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Joana Tavares (Author) FFUP; Ali Ouaissi (Author) Other; Nuno Santarem (Author) Other; Denis Sereno (Author) Other; Baptiste Vergnes (Author) Other; Paula Sampaio (Author) Other; Anabela Cordeiro Da Silva (Author) FFUP

Journal

Title: Biochemical Journal

Vol. 415 No. 3

Pages: 377-386

ISSN: 0264-6021

Publisher: PORTLAND PRESS LTD

Indexing

ISI Web of Knowledge - 34 Citations

ISI Web of Science

Scopus - 33 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-003-V02

DOI: 10.1042/bj20080666

Resumo (PT): Proteins of the SIR2 (Silent Information Regulator 2) family are characterized by a conserved catalytic domain that exerts unique NAD+-dependent deacetylase activity on histones and various other cellular substrates. Previous reports from us have identified a Leishmania infantum gene encoding a cytosolic protein termed LiSIR2RP1 (Leishmania infantum SIR2-related protein 1) that belongs to the SIR2 family. Targeted disruption of one LiSIR2RP1 gene allele led to decreased amastigote virulence, in vitro as well as in vivo. In the present study, attempts were made for the first time to explore and characterize the enzymatic functions of LiSIR2RP1. The LiSIR2RP1 exhibited robust NAD+-dependent deacetylase and ADP-ribosyltransferase activities. Moreover, LiSIR2RP1 is capable of deacetylating tubulin, either in dimers or, when present, in taxol-stabilized microtubules or in promastigote and amastigote extracts. Furthermore, the immunostaining of parasites revealed a partial co-localization of α-tubulin and LiSIR2RP1 with punctate labelling, seen on the periphery of both promastigote and amastigote stages. Isolated parasite cytoskeleton reacted with antibodies showed that part of LiSIR2RP1 is associated to the cytoskeleton network of both promastigote and amastigote forms. Moreover, the Western blot analysis of the soluble and insoluble fractions of the detergent of promastigote and amastigote forms revealed the presence of α-tubulin in the insoluble fraction, and the LiSIR2RP1 distributed in both soluble and insoluble fractions of promastigotes as well as amastigotes. Collectively, the results of the present study demonstrate that LiSIR2RP1 is an NAD+-dependent deacetylase that also exerts an ADP-ribosyltransferase activity. The fact that tubulin could be among the targets of LiSIR2RP1 may have significant implications during the remodelling of the morphology of the parasite and its interaction with the host cell. <br> <br> Key words: ADP-ribosyltransferase, cytoskeleton, Leishmania infantum SIR2-related protein 1 (LiSIR2RP1), NAD+-dependent deacetylase, parasite, α-tubulin. <br> <br>

Abstract (EN): Proteins of the SIR2 (Silent Information Regulator 2) family are characterized by a conserved catalytic domain that exerts unique NAD+-dependent deacetylase activity on histones and various other cellular substrates. Previous reports from us have identified a Leishmania infantum gene encoding a cytosolic protein termed LiSIR2RP1 (Leishmania infantum SIR2-related protein 1) that belongs to the SIR2 family. Targeted disruption of one LiSIR2RP1 gene allele led to decreased amastigote virulence, in vitro as well as in vivo. In the present study, attempts were made for the first time to explore and characterize the enzymatic functions of LiSIR2RP1. The LiSIR2RP1 exhibited robust NAD(+)-dependent deacetylase and ADP-ribosyltransferase activities. Moreover, LiSIR2RP1 is capable of deacetylating tubulin, either in dimers or, when present, in taxol-stabilized microtubules or in promastigote and amastigote extracts. Furthermore, the immunostaining of parasites revealed a partial co-localization Of alpha-tubulin and LiSIR2RP1 with punctate labelling, seen on the periphery of both promastigote and amastigote stages. Isolated parasite cyto skeleton reacted with antibodies showed that part of LiSIR2RP1 is associated to the cytoskeleton network of both promastigote and amastigote forms. Moreover, the Western blot analysis of the soluble and insoluble fractions of the detergent of prornastigote and amastigote forms revealed the presence of alpha-tubulin in the insoluble fraction, and the LiSIR2RP1 distributed in both soluble and insoluble fractions of promastigotes its well as amastigotes. Collectively, the results of the present study demonstrate that LiSIR2RP1 is an NAD(+)-dependent deacetylase that also exerts an ADP-ribosyltransferase activity. The fact that tall could be among the targets of LiSIR2RP1 may have significant implications during the remodelling of the morphology of the parasite and its interaction with the host cell.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10