TY - JOUR

T1 - Second nitrate reductase of Dunaliella salina: functional redundancy or greater?

AU - Залуцкая, Жаннета Михайловна

AU - Ермилова, Елена Викторовна

AU - Коркина, Софья Алексеевна

PY - 2023

Y1 - 2023

N2 - During evolution, algae have retained a single assimilatory nitrate reductase (NR), which governs the reduction of nitrate to nitrite. The unicellular green alga Dunaliella salina is a special case, as its cells have two NRs. This makes D. salina attractive to study the mechanisms underlying the nitrate assimilation in photosynthetic unicellular organisms. Here we characterize the expression of the gene encoding the second NR, named as DsaNIA1. Low levels of mRNA for DsaNIA1 are present in ammonia-grown cells. DsaNIA1 is a nitrate- and nitrite-inducible gene. Using spectrofluorometric assays with NO-sensitive fluorescence dye, we demonstrate nitrite-dependent NO synthesis by D. salina cells. Moreover, we found that the transcription of DsaNIA1, but not DsaNIA2, is under the inducing influence of NO-dependent pathway. Together, our data argue for the two differently regulated NR isoforms in D. salina.

AB - During evolution, algae have retained a single assimilatory nitrate reductase (NR), which governs the reduction of nitrate to nitrite. The unicellular green alga Dunaliella salina is a special case, as its cells have two NRs. This makes D. salina attractive to study the mechanisms underlying the nitrate assimilation in photosynthetic unicellular organisms. Here we characterize the expression of the gene encoding the second NR, named as DsaNIA1. Low levels of mRNA for DsaNIA1 are present in ammonia-grown cells. DsaNIA1 is a nitrate- and nitrite-inducible gene. Using spectrofluorometric assays with NO-sensitive fluorescence dye, we demonstrate nitrite-dependent NO synthesis by D. salina cells. Moreover, we found that the transcription of DsaNIA1, but not DsaNIA2, is under the inducing influence of NO-dependent pathway. Together, our data argue for the two differently regulated NR isoforms in D. salina.

KW - Dunaliella salina

KW - нитратредуктаза

KW - оксид азота

KW - Dunaliella salina

KW - nitrate reductase

KW - nitric oxide

UR - https://www.zin.ru/journals/Protistology/num17_1/num17_1.html

U2 - 10.21685/1680-0826-2022-17-1-2

DO - 10.21685/1680-0826-2022-17-1-2

M3 - Article

VL - 17

SP - 16

EP - 29

JO - Protistology

JF - Protistology

SN - 1680-0826

IS - 1

ER -