Amaprotheni e-DELLA ayalondolozwaabalawuli bokukhulaezidlala indima ebalulekile ekuthuthukisweni kwezitshalo ekuphenduleni izimpawu zangaphakathi nezangaphandle. Njengabalawuli bokuqopha, ama-DELLA abophezela ezintweni zokuqopha (ama-TF) kanye ne-histone H2A ngezizinda zawo ze-GRAS futhi aqashwa ukuthi asebenze kubagqugquzeli. Izifundo zakamuva zibonise ukuthi ukuzinza kwe-DELLA kulawulwa ngemuva kokuhumusha ngezindlela ezimbili: i-polyubiquitination ebangelwa yi-hormone yesitshalo.i-gibberellin, okuholela ekuwohlokeni kwazo ngokushesha, kanye nokuhlanganiswa ne-ubiquitin-like modifier encane (SUMO), okwandisa ukuqongelela kwazo. Ngaphezu kwalokho, umsebenzi we-DELLA ulawulwa ngokuguquguqukayo izindlela ezimbili ezihlukile ze-glycosylation: i-O-fucosylation ithuthukisa ukusebenzisana kwe-DELLA-TF, kanti ukuguqulwa kwe-O-linked N-acetylglucosamine (O-GlcNAc) kuvimbela ukusebenzisana kwe-DELLA-TF. Kodwa-ke, indima ye-DELLA phosphorylation ayicaci njengoba izifundo zangaphambilini zibonise imiphumela ephikisanayo, kanti ezinye ziphakamisa ukuthi i-phosphorylation ikhuthaza noma icindezela ukonakala kwe-DELLA kanti ezinye ziphakamisa ukuthi i-phosphorylation ayithinti ukuzinza kwazo. Lapha, sithola izindawo ze-phosphorylation ku-GA1-3 repressor (RGA), i-AtDELLA, ehlanjululwe ku-Arabidopsis thaliana nge-mass spectrometry futhi sibonisa ukuthi i-phosphorylation yama-peptide amabili e-RGA ezifundeni ze-PolyS kanye ne-PolyS/T ithuthukisa umsebenzi we-RGA ngokuthuthukisa ukubopha kwe-H2A kanye nokuhlangana kwe-RGA nabagqugquzeli abaqondiwe. Okuphawulekayo ukuthi i-phosphorylation ayizange ithinte ukusebenzisana kwe-RGA-TF noma ukuzinza kwe-RGA. Ucwaningo lwethu lwembula indlela yama-molecule lapho i-phosphorylation ibangela khona umsebenzi we-DELLA.
Ukuhlaziywa kwethu kwe-mass spectrometric kwembule ukuthi kokubili i-Pep1 ne-Pep2 zazine-phosphorylated kakhulu ku-RGA ngemuva kwe-GA-deficient Ga1. Ngaphezu kwalolu cwaningo, izifundo ze-phosphoproteomic nazo zembule i-Pep1 phosphorylation ku-RGA, yize indima yayo ingakafundwa53,54,55. Ngokuphambene nalokho, i-Pep2 phosphorylation ayikachazwa ngaphambilini njengoba le peptide ingatholakala kuphela kusetshenziswa i-RGAGKG transgene. Nakuba ukuguqulwa kwe-m1A, okwaqeda i-Pep1 phosphorylation, kunciphisa kancane umsebenzi we-RGA ku-planta, kwaba nomphumela wokwengeza lapho kuhlanganiswa ne-m2A ekunciphiseni umsebenzi we-RGA (Isithombe Esingeziwe 6). Okubalulekile, i-Pep1 phosphorylation yehliswe kakhulu ku-GA-enhanced sly1 mutant uma kuqhathaniswa ne-ga1, okuphakamisa ukuthi i-GA ikhuthaza i-RGA dephosphorylation, inciphisa umsebenzi wayo. Indlela i-GA ecindezela ngayo i-RGA phosphorylation idinga uphenyo olwengeziwe. Okunye okungenzeka ukuthi lokhu kufezwa ngokulawulwa kwe-protein kinase engaziwa. Nakuba izifundo zibonise ukuthi ukuvezwa kwe-CK1 protein kinase EL1 kwehliswa yi-GA ku-rice41, imiphumela yethu ikhombisa ukuthi ukuguqulwa kwe-Arabidopsis EL1 homologue ephezulu akunciphisi i-RGA phosphorylation. Ngokuvumelana nemiphumela yethu, ucwaningo lwamuva lwe-phosphoproteomic olusebenzisa imigqa ye-Arabidopsis AEL expressing kanye ne-ael triple mutant aluzange lubone noma yimaphi amaprotheni e-DELLA njengezingxenye zala ma-kinase56. Lapho silungiselela umbhalo, kwabikwa ukuthi i-GSK3, i-gene efaka i-kinase efana ne-GSK3/SHAGGY kukolweni (i-Triticum aestivum), ingakwazi ukufaka i-DELLA (Rht-B1b)57, yize i-phosphorylation ye-Rht-B1b yi-GSK3 ingakaqinisekiswa ku-planta. Ukusabela kwe-in vitro enzymatic lapho kukhona i-GSK3 kulandelwe ukuhlaziywa kwe-mass spectrometry kwembule izindawo ezintathu ze-phosphorylation ezitholakala phakathi kwezizinda ze-DELLA ne-GRAS ze-Rht-B1b (Isithombe Esingeziwe 3). Ukufakwa esikhundleni kwe-serine kuya ku-alanine kuzo zonke izindawo ezintathu ze-phosphorylation kuholele ekunciphiseni umsebenzi we-Rht-B1b kukolweni we-transgenic, okuhambisana nokutholakele kwethu ukuthi ukufakwa esikhundleni kwe-alanine ku-Pep2 RGA kunciphisa umsebenzi we-RGA. Kodwa-ke, ukuhlolwa kokuchithwa kwamaprotheni ku-in vitro kubonise ukuthi i-phosphorylation ingaphinde izinzise i-Rht-B1b57. Lokhu kuphambene nemiphumela yethu ekhombisa ukuthi ukufakwa esikhundleni kwe-alanine ku-Pep2 RGA akushintshi ukuzinza kwayo ku-planta. I-GSK3 kukolweni iyi-ortholog yeprotheyini engazweli i-brassinosteroid 2 (BIN2) ku-Arabidopsis 57. I-BIN2 iwumlawuli ongemuhle wokubonisa izimpawu ze-BR, futhi i-BR isebenzisa indlela yayo yokubonisa izimpawu ngokubangela ukuwohloka kwe-BIN2 58. Sibonise ukuthi ukwelashwa kwe-BR akunciphisi ukuzinza kwe-RGA 59 noma amazinga e-phosphorylation ku-Arabidopsis (Isithombe Esingeziwe 2), okuphakamisa ukuthi i-RGA cishe ayinakubizwa nge-phosphorylated yi-BIN2.
Yonke idatha yokulinganisa ihlaziywe ngokwezibalo kusetshenziswa i-Excel, futhi umehluko omkhulu wanqunywa kusetshenziswa ukuhlolwa kwe-t komfundi. Azikho izindlela zezibalo ezisetshenziswe ukunquma kusengaphambili usayizi wesampula. Akukho datha ekhishwe ekuhlaziyweni; ukuhlolwa akuzange kwenziwe ngokungahleliwe; futhi abacwaningi babenolwazi ngokwabiwa ngesikhathi sokuhlolwa kokuhlolwa komphumela. Osayizi besampula banikezwa ezinganekwaneni zezibalo nakumafayela edatha angahluziwe.
Isikhathi sokuthunyelwe: Ephreli-15-2025