ntr? keratohyalin granule

[gocentral]

Hi,

I've been reading papers about skin development and keratinization and keep coming across "keratohyalin granules" as a subcellular "structure" in the stratum granulosum of normal epidermal cells. So, I am wondering if we should have a GO term for this. However, I am not sure where we would put such a term. I don't have a good sense of teh structure, whether it's some sort of vesicle or just a protein deposit. The bolded phrase from the abstract below my help, but I really haven't found anything else informative.

I do see that the term "glycogen granule" (GO:0042587) is_a "cytoplasmic_part". Perhaps that is all we would be able to say about keratohyalin granules. There are several different proteins, or at least precursors, found in keratohyalin granules.

thanks,

-Karen

1. J Invest Dermatol. 2005 May;124(5):998-1007.

Isolation and characterization of human repetin, a member of the fused gene family of the epidermal differentiation complex.

Huber M, Siegenthaler G, Mirancea N, Marenholz I, Nizetic D, Breitkreutz D, Mischke D, Hohl D.

Department of Dermatology, University Hospital of Lausanne, Lausanne, Switzerland.

The human repetin gene is a member of the "fused" gene family and localized in the epidermal differentiation complex on chromosome 1q21. The "fused" gene family comprises profilaggrin, trichohyalin, repetin, hornerin, the profilaggrin-related protein and a protein encoded by c1orf10. Functionally, these proteins are associated with keratin intermediate filaments and partially crosslinked to the cell envelope (CE). Here, we report the isolation and characterization of the human repetin gene and of its protein product. The repetin protein of 784 amino acids contains EF (a structure resembling the E helix-calcium-binding loop-F helix domain of parvalbumin) hands of the S100 type and internal tandem repeats typical for CE precursor proteins, a combination which is characteristic for "fused" proteins. Repetin expression is scattered in the normal epidermis but strong in the acrosyringium, the inner hair root sheat and in the filiform papilli of the tongue. Ultrastructurally, repetin is a component of cytoplasmic non-membrane "keratohyalin" F-granules in the stratum granulosum of normal epidermis, similar to profilaggrin. Finally, we show that EF hands are functional and reversibly bind Ca(2+). Our results indicate that repetin is indeed a member of the fused gene family similar to the prototypical members profilaggrin and trichohyalin.

PMID: 15854042

Reported by: krchristie

Original Ticket: geneontology/ontology-requests/10572

[gocentral]

• assigned_to: RFoulger

Original comment by: rebeccafoulger

[gocentral]

• labels: --> New term request, cellular component
• status: open --> closed-accepted

Original comment by: rebeccafoulger

[gocentral]

Added: keratohyalin granule ; GO:0036457

(under cytoplasmic part)

Thanks, Becky

Original comment by: rebeccafoulger