Physcomitrella HMGA-type proteins display structural differences compared to their higher plant counterparts.
High mobility group (HMG) proteins of the HMGA family are chromatin-associated proteins that act as architectural factors in nucleoprotein structures involved in gene transcription. To date, HMGA-type proteins have been studied in various higher plant species, but not in lower plants. We have identified two HMGA-type proteins, HMGA1 and HMGA2, encoded in the genome of the moss model Physcomitrella patens. Compared to higher plant HMGA proteins, the two Physcomitrella proteins display some structural differences. Thus, the moss HMGA proteins have six (rather than four) AT-hook DNA-binding motifs and their N-terminal domain lacks similarity to linker histone H1. HMGA2 is expressed in moss protonema and it localises to the cell nucleus. Typical of HMGA proteins, HMGA2 interacts preferentially with A/T-rich DNA, when compared with G/C-rich DNA. In cotransformation assays in Physcomitrella protoplasts, HMGA2 stimulated reporter gene expression. In summary, our data show that functional HMGA-type proteins occur in Physcomitrella.
Lyngaard
Carina
C
Department of Life Sciences, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark.
Stemmer
Christian
C
Stensballe
Allan
A
Graf
Manuela
M
Gorr
Gilbert
G
Decker
Eva
E
Grasser
Klaus D
KD
D000225:Adenine / Q000378:metabolism; D000595:Amino Acid Sequence; D019068:Bryopsida / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D025741:HMGA1a Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D025743:HMGA2 Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013941:Thymine / Q000378:metabolism; D014170:Transformation, Genetic
C107092:HMGA1a Protein, plant; D025743:HMGA2 Protein; D010940:Plant Proteins; D011994:Recombinant Proteins; D025741:HMGA1a Protein; D004247:DNA; D000225:Adenine; D013941:Thymine