Three parallel linkage groups of human acidic keratin genes.

Two regions of human genomic DNA, each containing several keratin genes, were isolated and partially sequenced. The keratin genes are inactive, having suffered deleterious mutations. Both regions contain at least four keratin genes arranged in a head-to-tail orientation including a pseudogene for keratin K#16.

Embryonic expression of the human 40-kD keratin: evidence from a processed pseudogene sequence.

Analysis of the cytoskeletal components of early murine embryos has detected expression of two keratin proteins, K#8 and K#18, at the 4-8-cell stage. Comparable data for human embryos do not exist, although several processed pseudogenes corresponding to K#8 and K#18 have been discovered in the human genome. Because only genes that are expressed in pre-germ-line and germ-line cells can give rise to processed pseudogenes, the existence of human K#8 and K#18 processed pseudogenes is prima facie evidence for expression of keratins K#8 and K#18 in the early human embryo.

Inactivation of human keratin genes: the spectrum of mutations in the sequence of an acidic keratin pseudogene.

Keratins are cytoskeletal proteins encoded by a multigene family. We have identified the first human keratin pseudogene and determined its complete nucleotide sequence. Sequence comparisons indicate that the pseudogene arose from a very recent duplication of the 50-kd keratin (K14) gene.

Alkaline protease deficiency in the cr-1 (crisp) mutant of Neurospora crassa.

The adenyl cyclase deficient cr-1 mutant of Neurospora crassa grew poorly in bovine serum albumin as an alternative and only source of either sulfur, nitrogen or carbon. The low growth of the cr-1 mutant in protein was correlated with limited secretion of extracellular alkaline protease. The defect was specific for the cr-1 mutant and was suppressed by exogenous cyclic AMP.