The reference OMIM entry for this protein is 171900

Phosphoglucomutase 1; pgm1

DESCRIPTION

Phosphoglucomutases (PGM; EC 5.4.2.2) catalyze the transfer of phosphate between the 1 and 6 positions of glucose. Isozymes of PGM are monomeric, with molecular masses of about 60 kD, and are encoded by several genes, including PGM1. In most cell types, PGM1 isozymes predominate, representing about 90% of total PGM activity. One exception is red cells, where PGM2 (172000) is a major isozyme (Putt et al., 1993).

CLONING

Hopkinson and Harris (1966) presented evidence for the existence of at least 2 structural PGM loci, PGM1 and PGM2. Whitehouse et al. (1992) isolated a cDNA encoding human PGM1. Eighteen amino acid differences were found between human and rabbit PGM1. Southern blot analysis indicated that PGM1 is conserved among a wide variety of vertebrates ranging from primates to birds and amphibia. No evidence for PGM1-related sequences was found either by Southern blot analysis or by in situ hybridization. Thus, if the genes encoding human PGM2 and PGM3 (172100) arose by duplication from the same ancestral gene as PGM1, it seems likely that less than 65% sequence homology has been preserved. In addition to the ubiquitously expressed Pgm1 transcript, a fast muscle-specific Pgm1 transcript, designated Pgm1fm, exists in rabbit. By PCR using primers derived from the 5-prime end of rabbit Pgm1fm, Putt et al. (1993) isolated human PGM1FM. Human PGM1 and PGM1FM contain alternative first exons, and the deduced PGM1FM protein contains 18 additional N-terminal amino acids compared with PGM1. Human PGM1FM appeared to be expressed at low levels in fast muscle only.

GENE STRUCTURE

Putt et al. (1993) determined that the PGM1 gene contains 12 exons, including 2 alternative first exons, exons 1A and 1B, that are specific to the ubiquitous PGM1 transcript and the fast muscle PGM1 transcript, respectively. PGM1 spans more than 65 kb, with about 29 kb separating exons 1A and 1B. The region encompassing exon 1A has features characteristic of a housekeeping promoter, including high GC content, high incidence of CpG dinucleotides, lack of TATA or CCAAT boxes, and 6 Sp1 (189906)-binding sites. In contrast, the region encompassing exon 1B is not GC rich, has a low incidence of CpG dinucleotides, and lacks Sp1-binding sites as well as TATA or CCAAT boxes, features consistent with a nonhousekeeping promoter.

MAPPING

Parrington et al. (1968) found that the PGM1, PGM2, and PGM3 genes are not closely linked. By cell hybridization, synteny of PGM1 and peptidase C (PEPC; 170000) was demonstrated by Billardon et al. (1973). These loci are on chromosome 1. Douglas et al. (1973) demonstrated that the PGM1 and 6PGD (PGD; 172200) genes are on the distal end of the short arm of chromosome 1. Assuming that each arm of chromosome 1 is 140 male cM in length, Cook et al. (1974) concluded that, measured from the centromere, map positions are as follows: PGD 1p124; Rh (see 111680) 1p109; PGM1 1p079; Fy (110700) 1p010, PEPC 1q030. The Goss-Harris method of mapping by radiation-induced gene segregation combines features of recombinational study in families and synteny tests in hybrid cells. As applied to chromosome 1, the method shows that AK2 (103020) and UMPK (CMPK1; 191710) are distal to PGM1 and that the order of the genes is PGM1--UMPK--AK2/alpha-FUC (FUCA1; 612280)--ENO1 (172430) (Goss and Harris, 1977). On the basis of a family segregating for elliptocytosis (611804) and PGD, as well as the common polymorphisms Rh, P ... More on the omim web site

Subscribe to this protein entry history

Oct. 20, 2018: Protein entry updated
Automatic update: OMIM entry 171900 was added.

Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).