PsaH | PSI-H subunit of photosystem I (plants)

Arachis hypogaea, Brassica rapa, Medicago truncatula, Nicotiana sylvestris, Nicotiana tabaccum, Populus trichocarpa, Ricinus communis

Application example

2 µg of total leaf of Arabidopsis thaliana (1) and Hordeum vulgare (2) and cellular protein of Chlamydomonas reinhardtii (3) and Synechococcus PCC 7942 (4) isolated with PEB (AS08 300) were separated on 4-12% Nupage Bis-Tris gels in in MES running buffer (Invitrogen) at 200V for 35 minutes. Proteins were transferred for 80 minutes at 30V to a PVDF membrane pre-wetted in methanol and equilibrated in 1X transfer buffer. Blots were blocked immediately following transfer in 2% blocking reagent in 20 mM Tris, 137 mM sodium chloride pH 7.6 with 0.1% (v/v) Tween-20 (TBS-T) and probed with anti-PsaH (AS06 105, 1:1000) and secondary HRP-conjugated goat anti-rabbit antibody (1:50 000) for 1 hr in TBS-T containing 2% ECL Advance blocking reagent (GE Healthcare). Antibody incubations were followed by washings in TBS-T (15, +5, +5, +5 min). All steps were performed at RT with agitation. Signals was detected after 10 s using chemiluminescence detection reagent according to the manufacturers instructions and a CCD imager (FluorSMax, Bio-Rad).

PsaH (PSI-H) is a conserved subunit of type I photosynthetic reaction centers (Photosystem I, PSI). PSI is an integral membrane multi-protein complex that catalyzes the electron transfer from plastocyanin (or cytochrome c6) to ferredoxin (or flavodoxin). Psa-H has been suggested to be involved in regulation of state1-state2 transitions. In plants and algae Psa-H is nuclear encoded and imported post-translationally into the chloroplast where it inserts into the thylakoid membrane.