New perspectives on the plant PARP family: Arabidopsis PARP3 is inactive, and PARP1 exhibits predominant poly (ADP-ribose) polymerase activity in response to DNA damage.

BACKGROUND:Poly (ADP-ribosyl) ation (PARylation) is an important posttranslational modification that regulates DNA repair, gene transcription, stress responses and developmental processes in multicellular organisms. Poly (ADP-ribose) polymerase catalyzes PARylation by consecutively adding ADP-ribose moieties from NAD⁺ to the amino acid receptor residues on target proteins. Arabidopsis has three canonical members, and two of these members, and have been demonstrated to be bona fide poly (ADP-ribose) polymerases and to regulate DNA repair and stress response processes. However, it remains unknown whether a member that is highly expressed in seeds, has similar biochemical activity to that of AtPduanyu371 and Additionally, although both the phylogenetic relationships and structural similarities indicate that AtPduanyu371 and correspond to animal and respectively, two previous studies have indicated that AtPduanyu372, and not accounts for most of the Pduanyu37 activity in Arabidopsis, which is contrary to the knowledge that Pduanyu371 is the predominant Pduanyu37 in animals. RESULTS:In this study, we obtained both in vitro and in vivo evidence demonstrating that does not act as a typical Pduanyu37 in Arabidopsis. Domain swapping and point mutation assays indicated that AtPduanyu373 has lost NAD⁺-binding capability and is inactive. In addition, our results showed that AtPduanyu371 was responsible for most of the Pduanyu37 enzymatic activity in response to the DNA damage-inducing agents zeocin and methyl methanesulfonate (MMS) and was more rapidly activated than AtPduanyu372, which supports that AtPduanyu371 remains the predominant Pduanyu37 member in Arabidopsis. AtPduanyu371 might first become activated by binding to damaged sites, and AtPduanyu372 is then poly (ADP-ribosyl) ated by AtPduanyu371 in vivo. CONCLUSIONS:Collectively, our biochemical and genetic analysis results strongly support the notion that AtPduanyu373 has lost poly (ADP-ribose) polymerase activity in plants and performs different functions from those of AtPduanyu371 and AtPduanyu372. AtPduanyu371, instead of AtPduanyu372, plays the predominant role in PAR synthesis in both seeds and seedlings. These data bring new insights into our understanding of the physiological functions of plant Pduanyu37 family members.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}