8.A.234.  The Modifier of Hyperactive ACD6 (MHA1) Family 

The ACD6.1 or MHA1 proteins are small proteins that modulate ion-channel-like ACD6 (TC# 9.A.43.1.14) to regulate immunity in Arabidopsis thaliana. Two loci, MODULATOR OF HYPERACTIVE ACD6.1 (MHA1) and its paralog MHA1-LIKE (MHA1L), that code for approximately 7 kDa proteins, differentially interact with specific ACD6 variants. MHA1L enhances the accumulation of an ACD6 complex, thereby increasing the activity of the ACD6 standard allele for regulating plant growth and defenses. The intracellular ankyrin repeats of ACD6 are structurally similar to those found in mammalian ion channels. Several lines of evidence link increased ACD6 activity to enhanced calcium influx, with MHA1L is a direct regulator of ACD6, indicating that peptide-regulated ion channels are not restricted to animals (Chen et al. 2023).


 

References:

Chen, J., L. Li, J.H. Kim, B. Neuhäuser, M. Wang, M. Thelen, R. Hilleary, Y. Chi, L. Wei, K. Venkataramani, M. Exposito-Alonso, C. Liu, J. Keck, A.C. Barragan, R. Schwab, U. Lutz, Z.M. Pei, S.Y. He, U. Ludewig, D. Weigel, and W. Zhu. (2023). Small proteins modulate ion-channel-like ACD6 to regulate immunity in Arabidopsis thaliana. Mol. Cell. [Epub: Ahead of Print]
Examples:

TC#NameOrganismal TypeExample
8.A.234.1.1

The modifier of ACD6 putative ion channel (TC# 9.A..43.1.14), MHA1, that regulates immunity in A. thaliana (see family description) (Chen et al. 2023). 

MHA1 of Arabidopsis thaliana

 
8.A.234.1.2

Homolog of MHA1 (possibly MHA1L) of 72 aas

MHA1L of Arabidopsis thaliana

 
8.A.234.1.3

Homolog of MHA1 as an C-terminal domain of a much larger protein of 644 aas and possibly several TMSs. The C-terminal domain is 67% identical to MNA1.

Homolog of MHA1 in Arabidopsis thaliana

 
8.A.234.1.4

Uncharacterized protein of 91 aas.

UP of Asparagus officinalis (garden asparagus)

 
8.A.234.1.5

Uncharacterized protein of 151 aas and 1 or 2 TMSs in the N-terminal half of the protein which is not homologous to other members of this family in TCDB.

UP of Olea europaea subsp. europaea