Synechocystis sp.PCC 6803(hereafter:Synechocystis)is a model organism for studying photosynthesis,energy metabolism,and environmental stress.Although known as the first fully sequenced phototrophic organism,Synechocystis still has almost half of its proteome without func-tional annotations.In this study,by using co-fractionation coupled with liquid chromatography-tandem mass spectrometry(LC-MS/MS),we define 291 multi-protein complexes,encompassing 24,092 protein-protein interactions(PPIs)among 2062 distinct gene products.This information not only reveals the roles of photosynthesis in metabolism,cell motility,DNA repair,cell division,and other physiological processes,but also shows how protein functions vary from bacteria to higher plants due to changes in interaction partners.It also allows us to uncover the functions of hypothetical proteins,such as S110445,S110446,and S110447 involved in photosynthesis and cell motility,and Sill 334 involved in regulation of fatty acid biogenesis.Here we present the most exten-sive PPI data for Synechocystis so far,which provide critical insights into fundamental molecular mechanisms in cyanobacteria.

ObjectiveTo observe the lower limb muscle activation strategy of healthy middle-aged and old women during stair ascent and descent with surface electromyography. MethodsFrom August, 2021 to February, 2022, 20 healthy middle-aged and old women were measured the surface electromyography root mean square (RMS) and integrated electromyography (iEMG) of bilateral vastus lateral, rectus femoris, vastus medialis, biceps femoris and semitendinosus during stair ascent and descent, and co-contraction ratio was calculated. ResultsDuring stair ascent, the RMS of bilateral vastus lateral, rectus femoris and vastus medialis was higher at starting stage than at following stage (|t| > 6.650, P < 0.001), while the RMS of biceps femoris and semitendinosus was lower (t > 3.559, P < 0.01); and the co-contraction ratio of hamstrings/quadriceps was lower at starting stage than at following stage (t > 8.185, P < 0.001). During stair descent, the RMS of bilateral vastus lateral, vastus medialis, biceps femoris and semitendinosus was higher at following stage than at starting stage (t > 2.345, P < 0.05), as well as the co-contraction ratio of hamstrings/quadriceps (t > 2.405, P < 0.05). ConclusionThe activities of the muscles around the knees are almost symmetrical during stair ascent and descent for healthy middle-aged and old women. The activation and co-contraction ratio of quadriceps and hamstring are various at starting/following stages.