ARTÍCULO

N-terminal acetylome analyses and functional insights of the N-terminal acetyltransferase NatB

Autores: Van Damme, P.; Lasa Ventura, Marta; Polevoda, B.; Gazquez López, Cristina; Elosegui-Artola, A.; Kim, D.S.; Juan Pardo, María Elena; Demeyer, K.; Hole, K.; Larrea Leoz, María Esther; Timmerman, E.; Prieto Valtueña, Jesús María; Arnesen, T.; Sherman, F.; Gevaert, K.; Aldabe Arregui, Rafael
Título de la revista: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
ISSN: 0027-8424
Volumen: 109
Número: 31
Páginas: 12449 - 12454
Fecha de publicación: 2012
Lugar: WOS
Resumen:
Protein N-terminal acetylation (Nt-acetylation) is an important mediator of protein function, stability, sorting, and localization. Although the responsible enzymes are thought to be fairly well characterized, the lack of identified in vivo substrates, the occurrence of Nt-acetylation substrates displaying yet uncharacterized N-terminal acetyltransferase (NAT) specificities, and emerging evidence of posttranslational Nt-acetylation, necessitate the use of genetic models and quantitative proteomics. NatB, which targets Met-Glu-, Met-Asp-, and Met-Asn-starting protein N termini, is presumed to Nt-acetylate 15% of all yeast and 18% of all human proteins. We here report on the evolutionary traits of NatB from yeast to human and demonstrate that ectopically expressed hNatB in a yNatB-Delta yeast strain partially complements the natB-Delta phenotypes and partially restores the yNatB Nt-acetylome. Overall, combining quantitative N-terminomics with yeast studies and knockdown of hNatB in human cell lines, led to the unambiguous identification of 180 human and 110 yeast NatB substrates. Interestingly, these substrates included Met-Gln- N-termini, which are thus now classified as in vivo NatB substrates. We also demonstrate the requirement of hNatB activity for maintaining the structure and function of actomyosin fibers and for proper cellular migration. In addition, expression of tropomyosin-1 restored the altered focal adhesions and cellular migration defects observed in hNatB-depleted HeLa cells, indicative for the conserved link between NatB, tropomyosin, and actin cable function from yeast to human.