MAP11

Primary transcript of C7orf43 isoform 1, showing 11 exons and 10 introns (NCBI Aceview:C7orf43)

MAP11 encodes 2 isoforms, the longest being C7orf43 isoform 1, which is 2585 base pairs long and has with 11 exons and 10 introns.[1] C7orf43 isoform 1 encodes a protein that is 580 amino acids long and only has one polyadenylation site.[1] C7orf43 isoform 2 is 2085 base pairs long and encodes a protein of 311 amino acids. Two additional isoforms has been reported on several occasions, encoding for proteins with 199 and 206 amino acids.[4]

MAP11 has a widespread moderate expression with tissue to tissue variability in humans and across mammalian species.[5][6] The mouse C7orf43 ortholog has been shown to be ubiquitously expressed in the brain,[7] as well as in the mouse embryonic central nervous system.[8]

MAP11 has one promoter region upstream of its transcription site, as predicted by Genomatix. This promoter is 657 base pairs long and is located at position 99756182 to 99756838 in the negative strand of chromosome 7.[9] There are several transcription factor binding sites located in this promoter, including binding sites for zinc fingers and Kruppel-like transcription factors.[10] The top 20 transcription binding sites as predicted by the ElDorado from Genomatix is listed in the following table.

The human protein MAP11 has an isoelectric point of 8.94. MAP11 also has a glycine-rich region spanning amino acids 54 through 134.[11] Analysis using the SAPS tool from the SDSC Biology Workbench showed this glycine-rich region to not be conserved in terms of specific glycine residue positions, but is well conserved in overall glycine content in mammals and reptiles, although not in bony fishes.[12][13] C7orf43 is mostly uncharged, and this neutral charge distribution is conserved in mammals and reptiles, but bony fishes have at least one negative charge cluster [12][13] C7orf43 is predicted to have no signal peptide in its first 70 amino acid residues. However, it is predicted to have a vacuolar targeting motif starting at residue 258 in the human protein.[14] This vacuolar targeting motif is shown to be conserved throughout mammals, reptiles, birds, amphibians, and bony fishes.

The MAP11 protein has no paralogs in humans. However, C7orf43 orthologs can be found to be highly conserved in mammals, reptiles, and several species of bony fishes. C7orf43 is also conserved in birds, although several bird species lack parts of the N-terminus.[15] No C7orf43 orthologs can be found outside the animal kingdom.[15] The following table lists representative C7orf43 orthologs across multiple animal classes.

C7orf43 has three phosphorylated sites, Ser 517, Thr 541 and, Ser 546.[11] All three sites are relatively well-conserved throughout mammals, reptiles, birds, amphibians, and bony fishes. The protein has no predicted N-myristoylation, as it has no N-terminal glycine.[16] However, C7orf43 is predicted to have one N-acetylation on a serine residue at the N-terminus.[17]

The secondary structure of C7orf43 is yet to be determined. However, C7orf43 is predicted to have no transmembrane domain and to eventually be secreted from the cell.[18][19] An analysis using the PELE tool from SDSC Biology Workbench predicted mostly beta sheets and random coils that are conserved throughout the strict orthologs.[13] Similarly conserved alpha helix motifs have been predicted, one near the N-terminus and one near the C-terminus.