Human SP-A: then and now.
In the short span of ten years, our understanding of human surfactant-associated protein A (SP-A) has advanced rapidly at both the level of the protein and the level of the gene. In the period 1984-1988, the protein was biochemically characterized and two SP-A precursors were identified. The molecular characterization was begun with the publication of an SP-A genomic sequence and sequences of two SP-A cDNAs, suggesting the presence of two SP-A genes. In the period 1991-1992, an SP-A pseudogene, a second SP-A genomic sequence, and an SP-A allelic variant were described. Since that time, a picture of increasing complexity has emerged from studies of the two SP-A genes. This complexity includes alternative splicing of 5' untranslated exons, allelic variants of both SP-A genes, and sequence heterogeneity within the 3' untranslated region. The challenge for the future will be to discover the physiological significance of the genetic complexity of human SP-A.
Floros
J
J
Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey 17033.
Karinch
A M
AM
D000483:Alleles; D000818:Animals; D005796:Genes; D014644:Genetic Variation; D016678:Genome; D006023:Glycoproteins / Q000502:physiology; D006801:Humans; D010827:Physiology / Q000639:trends; D011510:Proteolipids / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D006023:Glycoproteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants