High impact information on PAS2

• Loss of the PAS2 function dephosphorylated Arabidopsis thaliana CDKA;1 and upregulated its kinase activity [1].
• In accordance with its role as a negative regulator of the cell cycle, overexpression of PAS2 slowed down cell division in suspension cell cultures at the G2-to-M transition and early mitosis and inhibited Arabidopsis seedling growth [1].
• Phosphorylation of the conserved regulatory Tyr-15 is involved in the binding of CDK to PAS2 [1].
• PASTICCINO2 (PAS2), a member of the protein Tyr phosphatase-like family, is conserved among all eukaryotes and is characterized by a mutated catalytic site [1].
• Missense mutation in the PAS2 domain of phytochrome A impairs subnuclear localization and a subset of responses [2].

Biological context of PAS2

• PAS2 was localized in the cytoplasm of dividing cells but moved into the nucleus upon cell differentiation, suggesting that the balance between cell division and differentiation is regulated through the interaction between CDKA;1 and the antiphosphatase PAS2 [1].
• However, comparison of expression patterns of Cyclin1At and the homeobox gene KNAT2 indicates that PEPINO ( PEP) is involved in cell cycle regulation of meristematic and non-meristematic cells [3].
• Mutants of the Arabidopsis gene PEPINO/PASTICCINO2 develop abnormal shoot phenotypes from slow tumour-like cell proliferation [3].

Associations of PAS2 with chemical compounds

• Abnormal proliferation is enhanced in a mutant background, which elevates endogenous cytokinin levels as seen in double mutants of pepino and altered meristem primordia1 [3].

Other interactions of PAS2

• This PHYA core region contains two protein-interactive motifs, PAS1 and PAS2 [4].
• We propose that the PAS2 domain of phytochrome A is necessary to initiate signaling in HIR but not in VLFR, likely via interaction with a specific partner [2].

References