HMGA1
Function
HMG-I/Y bind preferentially to the minor groove of A+T rich regions in double-stranded DNA. It is suggested that these proteins could function in nucleosome phasing and in the 3'-end processing of mRNA transcripts. They are also involved in the transcription regulation of genes containing, or in close proximity to A+T-rich regions.
Involvement in disease
A chromosomal aberration involving HMGA1 is found in pulmonary chondroid hamartoma. Translocation t(6;14)(p21;q23-24) with RAD51B.
Post-translational modifications
Constitutively phosphorylated on two or three sites. Hyperphosphorylated at early stages of apoptosis, followed by dephosphorylation and methylation, which coincides with chromatin condensation. Isoforms HMG-I and HMG-Y can be phosphorylated by HIPK2. Phosphorylation of HMG-I at Ser-36, Thr-53 and Thr-78 and of HMG-Y at Thr-42 and Thr-67 by HIPK2 modulates DNA-binding affinity.
HMG-Y is not methylated.
Methylation at Arg-58 is mutually exclusive with methylation at Arg-60.
Sequence Similarities
Belongs to the HMGA family.
Cellular localization
- Nucleus
- Chromosome
Alternative names
HMGIY, HMGA1, High mobility group protein HMG-I/HMG-Y, HMG-I(Y), High mobility group AT-hook protein 1, High mobility group protein R, High mobility group protein A1